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2025-04-28 00:58:08
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A381215 | Numbers k such that the difference between the largest and smallest element of the set of bases and exponents (including exponents = 1) in the prime factorization of k is 1. | [
"2",
"8",
"9",
"36",
"72",
"81",
"108",
"216",
"625",
"15625",
"117649",
"5764801",
"25937424601",
"3138428376721",
"23298085122481",
"3937376385699289",
"48661191875666868481",
"14063084452067724991009",
"104127350297911241532841",
"37589973457545958193355601",
"907846434775996175406740561329"
] | [
"nonn",
"easy"
] | 19 | 1 | 1 | [
"A036878",
"A081812",
"A104126",
"A381212",
"A381214",
"A381215",
"A381317"
] | null | Paolo Xausa, Feb 19 2025 | 2025-02-21T09:31:32 | oeisdata/seq/A381/A381215.seq | b564d8072b905fb19a234b74470bdb80 |
A381216 | Number of isomers of C_n H_{2n+2} O_2. | [
"1",
"2",
"5",
"11",
"28",
"69",
"179",
"463",
"1225",
"3246",
"8697",
"23366",
"63137",
"171051",
"465002",
"1266831",
"3459262",
"9462393",
"25926939",
"71139400",
"195451500",
"537608802",
"1480316960",
"4079977874",
"11254956840",
"31072771980",
"85850016944",
"237356027117",
"656657132953",
"1817758531055",
"5034725293449"
] | [
"nonn"
] | 10 | 0 | 2 | [
"A000598",
"A000599",
"A000600",
"A000602",
"A000635",
"A000636",
"A381216"
] | null | Erich Friedman, Feb 17 2025 | 2025-02-18T19:40:35 | oeisdata/seq/A381/A381216.seq | 2b1fed5362cf3c26ddb2c9736abe5747 |
A381217 | a(n) is the least positive k such that the sum of the reverses of the first k primes is divisible by n. | [
"1",
"1",
"10",
"5",
"2",
"16",
"5",
"20",
"20",
"3",
"9",
"16",
"7",
"5",
"10",
"30",
"4",
"20",
"68",
"44",
"16",
"20",
"9",
"20",
"19",
"7",
"26",
"5",
"47",
"34",
"19",
"30",
"20",
"28",
"99",
"20",
"29",
"68",
"54",
"44",
"86",
"16",
"41",
"20",
"74",
"26",
"40",
"30",
"16",
"50",
"28",
"82",
"97",
"26",
"101",
"51",
"68",
"47",
"6",
"44",
"38",
"53",
"42",
"30",
"7",
"20",
"38",
"28",
"10",
"99",
"110",
"20",
"72",
"121",
"103",
"137",
"189"
] | [
"nonn",
"base"
] | 13 | 1 | 3 | [
"A071602",
"A381217"
] | null | Robert Israel, Feb 17 2025 | 2025-02-19T11:21:03 | oeisdata/seq/A381/A381217.seq | f9abbd4c8c1945fe8c8094814f550595 |
A381218 | Odd numbers with both an odd number of prime factors (counted with multiplicity) and an odd number of distinct prime factors. (Intersection of A067019 and A098903.) | [
"3",
"5",
"7",
"11",
"13",
"17",
"19",
"23",
"27",
"29",
"31",
"37",
"41",
"43",
"47",
"53",
"59",
"61",
"67",
"71",
"73",
"79",
"83",
"89",
"97",
"101",
"103",
"105",
"107",
"109",
"113",
"125",
"127",
"131",
"137",
"139",
"149",
"151",
"157",
"163",
"165",
"167",
"173",
"179",
"181",
"191",
"193",
"195",
"197",
"199",
"211",
"223",
"227",
"229",
"231",
"233",
"239"
] | [
"nonn",
"easy"
] | 8 | 1 | 1 | [
"A067019",
"A098903",
"A381218"
] | null | Harvey P. Dale, Feb 17 2025 | 2025-02-17T13:01:58 | oeisdata/seq/A381/A381218.seq | aaa305d71970361857c2f1084768b957 |
A381219 | a(n) = (6^n+2^n-2*3^n)*(n-1)!/2. | [
"1",
"11",
"170",
"3450",
"87864",
"2715720",
"99248400",
"4200210000",
"202383054720",
"10949741066880",
"657619863264000",
"43423960900320000",
"3127284944109849600",
"243957907264508236800",
"20493712266753293568000",
"1844490309401727187200000",
"177073768932670444843008000",
"18061662138488384327847936000",
"1950666948832313303630438400000"
] | [
"nonn"
] | 11 | 1 | 2 | [
"A379809",
"A381219"
] | null | N. J. A. Sloane, Feb 17 2024, based on an email from David Broadhurst. | 2025-02-18T15:34:59 | oeisdata/seq/A381/A381219.seq | 3e5d0547acbdffe21b93cfd6f8bd2c05 |
A381220 | First differences of A381116. | [
"6",
"3",
"7",
"7",
"6",
"11",
"8",
"8",
"1",
"15",
"12",
"9",
"13",
"10",
"19",
"7",
"18",
"11",
"18",
"5",
"22",
"12",
"21",
"3",
"20",
"11",
"35",
"5",
"16",
"18",
"18",
"23",
"17",
"20",
"26",
"17",
"3",
"42",
"4",
"7",
"42",
"22",
"25",
"1",
"34",
"9",
"8",
"47",
"6",
"55",
"8",
"49",
"7",
"8",
"6",
"42",
"14",
"32",
"19",
"6",
"51",
"2",
"50",
"11",
"27",
"42",
"25",
"46",
"54",
"21",
"22",
"45",
"4",
"16",
"53",
"4",
"73",
"10",
"25",
"39",
"9",
"70",
"11",
"46",
"33",
"49",
"27",
"11",
"20",
"17"
] | [
"nonn"
] | 8 | 1 | 1 | [
"A381019",
"A381116",
"A381220",
"A381221"
] | null | N. J. A. Sloane, Feb 18 2025 | 2025-02-18T10:22:00 | oeisdata/seq/A381/A381220.seq | 2e3ad7b259f4a940170f6245e6b28f8a |
A381221 | Partial sums of A381116. | [
"6",
"9",
"16",
"23",
"29",
"40",
"48",
"56",
"57",
"72",
"84",
"93",
"106",
"116",
"135",
"142",
"160",
"171",
"189",
"194",
"216",
"228",
"249",
"252",
"272",
"283",
"318",
"323",
"339",
"357",
"375",
"398",
"415",
"435",
"461",
"478",
"481",
"523",
"527",
"534",
"576",
"598",
"623",
"624",
"658",
"667",
"675",
"722",
"728",
"783",
"791",
"840",
"847",
"855",
"861",
"903",
"917",
"949",
"968",
"974",
"1025",
"1027",
"1077",
"1088",
"1115",
"1157"
] | [
"nonn"
] | 6 | 1 | 1 | null | null | N. J. A. Sloane, Feb 18 2025 | 2025-02-18T10:25:41 | oeisdata/seq/A381/A381221.seq | b0467c8fc4377e11f97fa4d54602d081 |
A381222 | Smallest number missing from A381019 after A381019(n) has been found. | [
"2",
"3",
"4",
"4",
"4",
"4",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"10",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"18",
"18",
"18"
] | [
"nonn"
] | 10 | 1 | 1 | [
"A381019",
"A381119",
"A381222"
] | null | N. J. A. Sloane, Feb 19 2025 | 2025-02-20T04:45:30 | oeisdata/seq/A381/A381222.seq | edac3d382155a32ca9cf4358dc205838 |
A381223 | Take the list (A381222) of successive values of the smallest number missing from A381019, and keep just the first of any run of successive equal terms. | [
"2",
"3",
"4",
"6",
"10",
"14",
"18",
"24",
"26",
"30",
"34",
"36",
"42",
"44",
"45",
"46",
"50",
"52",
"54",
"56",
"58",
"60",
"66",
"72",
"76",
"78",
"84",
"90",
"96",
"100",
"102",
"108",
"110",
"112",
"114",
"120",
"122",
"124",
"126",
"130",
"136",
"138",
"144",
"150",
"156",
"160",
"162",
"168",
"170",
"172",
"174",
"176",
"180",
"186",
"188",
"190",
"192"
] | [
"nonn"
] | 11 | 1 | 1 | [
"A381019",
"A381222",
"A381223"
] | null | N. J. A. Sloane, Feb 20 2025 | 2025-02-20T23:47:59 | oeisdata/seq/A381/A381223.seq | 901069acfc9263f74193b5cfe054422c |
A381224 | a(n) is the integer resulting from the concatenation of the unit digit of prime(n-1) to the digits of prime(n) without its own unit digit. | [
"0",
"2",
"3",
"5",
"71",
"11",
"31",
"71",
"92",
"32",
"93",
"13",
"74",
"14",
"34",
"75",
"35",
"96",
"16",
"77",
"17",
"37",
"98",
"38",
"99",
"710",
"110",
"310",
"710",
"911",
"312",
"713",
"113",
"713",
"914",
"915",
"115",
"716",
"316",
"717",
"317",
"918",
"119",
"119",
"319",
"719",
"921",
"122",
"322",
"722",
"923",
"323",
"924",
"125",
"125",
"726",
"326",
"927",
"127",
"728",
"128",
"329",
"330",
"731",
"131",
"331",
"733",
"133",
"734",
"734",
"935",
"335"
] | [
"nonn",
"base",
"look"
] | 19 | 1 | 2 | [
"A000040",
"A032759",
"A290148",
"A339467",
"A381224"
] | null | N. J. A. Sloane, Feb 22 2025 | 2025-02-22T14:06:48 | oeisdata/seq/A381/A381224.seq | f934688a9ab9764308f662a09f7668cd |
A381225 | Index of first occurrence of n in A290148. | [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"91",
"101",
"12",
"22",
"32",
"42",
"52",
"62",
"72",
"82",
"92",
"201",
"13",
"23",
"33",
"43",
"53",
"63",
"73",
"83",
"93",
"301",
"14",
"24",
"34",
"44",
"54",
"64",
"74",
"84",
"94",
"401",
"15",
"25",
"35",
"45",
"55",
"65",
"75",
"85",
"95",
"501",
"16",
"26",
"36",
"46",
"56",
"66",
"76",
"86",
"96",
"601",
"17",
"27",
"37",
"47",
"57",
"67",
"77",
"87",
"97",
"701",
"18",
"28",
"38",
"48",
"58",
"68",
"78",
"88",
"98",
"801",
"19",
"29",
"39"
] | [
"nonn",
"base",
"look"
] | 10 | 0 | 2 | [
"A290148",
"A381225"
] | null | N. J. A. Sloane, Feb 23 2025 | 2025-02-23T09:02:58 | oeisdata/seq/A381/A381225.seq | 81056a8f9ad0d2f6eb122ac085aeb343 |
A381226 | a(n) is the number of distinct positive integers that can be obtained by starting with n!, and optionally applying the operations square root, floor, and ceiling, in any order. | [
"1",
"2",
"4",
"6",
"7",
"8",
"8",
"9",
"10",
"10",
"10",
"11",
"12",
"12",
"12",
"12",
"12",
"13",
"13",
"13",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"14",
"15",
"15",
"15",
"15",
"15",
"15",
"16",
"16",
"16",
"16",
"16",
"16",
"16",
"16",
"16",
"16",
"16",
"16",
"16",
"17",
"17",
"17",
"17",
"17",
"17",
"17",
"17",
"17",
"17",
"18",
"18",
"18",
"18",
"18",
"18",
"18",
"18",
"18",
"18",
"18"
] | [
"nonn"
] | 33 | 1 | 2 | [
"A000319",
"A139004",
"A381226",
"A381227",
"A381229"
] | null | N. J. A. Sloane, Feb 24 2025 | 2025-03-16T12:55:32 | oeisdata/seq/A381/A381226.seq | bc6b3210cbb9bfe6bd5c0b79b712a116 |
A381227 | Irregular triangle read by rows: row n lists the A381226(n) numbers constructed in the definition of A381226, in increasing order. | [
"1",
"1",
"2",
"1",
"2",
"3",
"6",
"1",
"2",
"3",
"4",
"5",
"24",
"1",
"2",
"3",
"4",
"10",
"11",
"120",
"1",
"2",
"3",
"5",
"6",
"26",
"27",
"720",
"1",
"2",
"3",
"8",
"9",
"70",
"71",
"5040",
"1",
"2",
"3",
"4",
"14",
"15",
"200",
"201",
"40320",
"1",
"2",
"3",
"4",
"5",
"24",
"25",
"602",
"603",
"362880",
"1",
"2",
"3",
"6",
"7",
"43",
"44",
"1904",
"1905",
"3628800",
"1",
"2",
"3",
"8",
"9",
"79",
"80",
"6317",
"6318",
"39916800"
] | [
"nonn",
"tabf"
] | 14 | 1 | 3 | [
"A139004",
"A381226",
"A381227",
"A381228",
"A381229"
] | null | N. J. A. Sloane, Feb 25 2025 | 2025-02-25T18:24:51 | oeisdata/seq/A381/A381227.seq | 95d9dba9051fd97597406b5ab233add7 |
A381228 | Smallest k such that n appears in row k of the triangle in A381227, or -1 if n never appears in A381227. | [
"1",
"2",
"3",
"4",
"4",
"3",
"10",
"7",
"7",
"5",
"5",
"12",
"12",
"8",
"8",
"13",
"13",
"21",
"36",
"22",
"22",
"37",
"14",
"4",
"9",
"6",
"6",
"39",
"39",
"24",
"24",
"15",
"15",
"69",
"41",
"41",
"25",
"25",
"42",
"42",
"72",
"72",
"10",
"10",
"43",
"16",
"16",
"74",
"128",
"44",
"44",
"75",
"130",
"76",
"76",
"27",
"27",
"77",
"77",
"134",
"134",
"78",
"46",
"46",
"17",
"17",
"79",
"79",
"28"
] | [
"nonn"
] | 12 | 1 | 2 | [
"A139004",
"A381226",
"A381227",
"A381228",
"A381229"
] | null | N. J. A. Sloane, Feb 25 2025 | 2025-02-28T05:13:29 | oeisdata/seq/A381/A381228.seq | 2c7107a4b37f0a04fdced506863bf564 |
A381229 | a(n) is the number of distinct positive integers that can be obtained by starting with n, and optionally applying the operations square root, floor, and ceiling, in any order. | [
"1",
"2",
"3",
"3",
"4",
"4",
"4",
"4",
"4",
"5",
"5",
"5",
"5",
"5",
"5",
"4",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"5",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"5",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"5",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"5",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"6",
"5",
"7",
"7",
"7",
"7",
"7",
"7"
] | [
"nonn"
] | 8 | 1 | 2 | [
"A381226",
"A381227",
"A381228",
"A381229"
] | null | N. J. A. Sloane and Jinyuan Wang, Feb 25 2025 | 2025-02-25T15:05:36 | oeisdata/seq/A381/A381229.seq | f045c8800bfcf78e74b5d323dbcc10d0 |
A381230 | Index of first occurrence of n in A000319, or -1 if n never appears there. | [
"6",
"0",
"17",
"45",
"13",
"42",
"938",
"920",
"57403",
"7865",
"15862",
"313445",
"54988",
"53976",
"57573",
"61372",
"83445",
"14998",
"360213",
"57322",
"59858",
"2070497",
"2021631",
"14918",
"58001",
"1394543",
"79664",
"2056395",
"85989",
"11",
"8",
"71662",
"5495575",
"5652770",
"360110",
"2070250",
"5947332",
"5514279",
"5514772",
"2015129",
"78877",
"305403",
"1031",
"1869352",
"5652707",
"4823241"
] | [
"nonn"
] | 51 | 0 | 1 | [
"A000319",
"A381230",
"A381231"
] | null | N. J. A. Sloane, Feb 28 2025 | 2025-03-14T02:34:32 | oeisdata/seq/A381/A381230.seq | a33ca61aff824b81aac6c97acbe553e2 |
A381231 | Index of first occurrence of -n in A000319, or -1 if -n never appears there. | [
"6",
"3",
"4",
"5",
"48",
"15642",
"14",
"87",
"924",
"23",
"1074",
"1066",
"14524",
"7051",
"15000",
"71709",
"57604",
"57554",
"2056626",
"2036049",
"16068",
"86",
"934",
"37142",
"57439",
"72635",
"57342",
"1394559",
"358329",
"2112076",
"16941",
"2015018",
"57124",
"27572",
"1837444",
"29",
"2058540",
"54694",
"2075246",
"359870",
"76579",
"7844",
"61424",
"55065",
"61434",
"2016279",
"71877",
"2271483",
"305269",
"57405",
"1842679"
] | [
"nonn"
] | 43 | 0 | 1 | [
"A000319",
"A381230",
"A381231"
] | null | N. J. A. Sloane, Feb 28 2025 | 2025-03-14T02:33:30 | oeisdata/seq/A381/A381231.seq | 2603b2eb6840b77eacaf8d26d17aaf66 |
A381232 | Count down from k to -k for k = 0, 1, 2, ... . | [
"0",
"1",
"0",
"-1",
"2",
"1",
"0",
"-1",
"-2",
"3",
"2",
"1",
"0",
"-1",
"-2",
"-3",
"4",
"3",
"2",
"1",
"0",
"-1",
"-2",
"-3",
"-4",
"5",
"4",
"3",
"2",
"1",
"0",
"-1",
"-2",
"-3",
"-4",
"-5",
"6",
"5",
"4",
"3",
"2",
"1",
"0",
"-1",
"-2",
"-3",
"-4",
"-5",
"-6",
"7",
"6",
"5",
"4",
"3",
"2",
"1",
"0",
"-1",
"-2",
"-3",
"-4",
"-5",
"-6",
"-7",
"8",
"7",
"6",
"5",
"4",
"3",
"2",
"1",
"0",
"-1",
"-2",
"-3",
"-4",
"-5",
"-6",
"-7",
"-8",
"9",
"8",
"7",
"6",
"5",
"4",
"3",
"2",
"1",
"0",
"-1",
"-2",
"-3",
"-4",
"-5",
"-6",
"-7",
"-8",
"-9"
] | [
"sign",
"easy"
] | 18 | 0 | 5 | [
"A196199",
"A381232",
"A381233"
] | null | N. J. A. Sloane, Mar 01 2025 [Suggested by Franklin T. Adams-Watters, Sep 21 2011] | 2025-03-02T08:01:42 | oeisdata/seq/A381/A381232.seq | d6b186820286e7859a4863e3e98fb235 |
A381233 | Concatenate the sequences S(k) = [0, 1, -1, ..., k, -k] for k = 0, 1, ... | [
"0",
"0",
"1",
"-1",
"0",
"1",
"-1",
"2",
"-2",
"0",
"1",
"-1",
"2",
"-2",
"3",
"-3",
"0",
"1",
"-1",
"2",
"-2",
"3",
"-3",
"4",
"-4",
"0",
"1",
"-1",
"2",
"-2",
"3",
"-3",
"4",
"-4",
"5",
"-5",
"0",
"1",
"-1",
"2",
"-2",
"3",
"-3",
"4",
"-4",
"5",
"-5",
"6",
"-6",
"0",
"1",
"-1",
"2",
"-2",
"3",
"-3",
"4",
"-4",
"5",
"-5",
"6",
"-6",
"7",
"-7",
"0",
"1",
"-1",
"2",
"-2",
"3",
"-3",
"4",
"-4",
"5",
"-5",
"6",
"-6",
"7",
"-7",
"8",
"-8",
"0",
"1",
"-1",
"2",
"-2",
"3",
"-3",
"4",
"-4",
"5",
"-5",
"6",
"-6",
"7",
"-7",
"8",
"-8",
"9",
"-9"
] | [
"sign",
"easy"
] | 10 | 0 | 8 | [
"A196199",
"A381232",
"A381233"
] | null | N. J. A. Sloane, Mar 01 2025 [Suggested by Franklin T. Adams-Watters, Sep 21 2011] | 2025-03-01T16:45:27 | oeisdata/seq/A381/A381233.seq | e88dad67a177e35968a33a1e23ad301e |
A381234 | RUNS transform of A000319. | [
"2",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"4",
"1",
"1",
"2",
"1",
"1",
"1",
"1",
"7",
"1",
"1",
"2",
"1",
"1",
"2",
"1",
"2",
"1",
"8",
"1",
"1",
"1",
"1",
"18",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"825",
"2",
"1",
"2",
"2",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"2",
"2",
"1",
"2",
"1",
"1",
"76",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"3",
"2",
"1",
"1",
"1",
"1",
"1",
"1",
"29",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"2",
"1",
"1",
"1144",
"1",
"1",
"188",
"1",
"1",
"4571",
"1",
"1",
"62"
] | [
"nonn"
] | 18 | 1 | 1 | [
"A000319",
"A381234",
"A381235"
] | null | N. J. A. Sloane, Mar 16 2025 | 2025-03-18T07:21:19 | oeisdata/seq/A381/A381234.seq | 3d72ab63cda51858674e7a20b9aeb9ca |
A381235 | a(n) = the term of A000319 that is repeated in the n-th run of equal consecutive terms. | [
"1",
"74",
"-1",
"-2",
"-3",
"0",
"1",
"30",
"-2",
"29",
"1",
"4",
"-6",
"0",
"1",
"2",
"-1",
"-2",
"-9",
"0",
"1",
"2",
"-2",
"-35",
"-1",
"-2",
"-3",
"0",
"1",
"5",
"-2",
"3",
"1",
"-4",
"-1",
"-2",
"-3",
"1",
"2",
"-1",
"-2",
"-3",
"0",
"1",
"2",
"-1",
"-2",
"-21",
"-7",
"0",
"1",
"-4",
"-1",
"-2",
"7",
"2",
"-3",
"1",
"-8",
"-3",
"1",
"-3",
"1",
"3",
"0",
"1",
"-22",
"0",
"1",
"6",
"-1",
"-2",
"-3",
"1",
"6",
"0",
"1",
"2",
"-1",
"-2",
"5",
"-3",
"1",
"42",
"-2",
"2",
"-1",
"-2",
"-3",
"1",
"-11",
"-1",
"-2",
"-4",
"-1"
] | [
"sign"
] | 9 | 1 | 2 | [
"A000319",
"A381234",
"A381235"
] | null | N. J. A. Sloane, Mar 16 2025. | 2025-03-16T22:55:56 | oeisdata/seq/A381/A381235.seq | 0482687bbc69925a2e541b91b0d1984b |
A381236 | Irregular triangle read by rows: to get row n, take all the numbers that can be obtained by permuting the digits of 9*n, divide them by 9, and arrange them in order. | [
"0",
"1",
"2",
"9",
"3",
"8",
"4",
"7",
"5",
"6",
"5",
"6",
"4",
"7",
"3",
"8",
"2",
"9",
"1",
"10",
"11",
"2",
"9",
"12",
"20",
"89",
"90",
"13",
"19",
"79",
"14",
"18",
"24",
"29",
"68",
"69",
"15",
"17",
"35",
"39",
"57",
"59",
"16",
"46",
"49",
"15",
"17",
"35",
"39",
"57",
"59",
"14",
"18",
"24",
"29",
"68",
"69",
"13",
"19",
"79",
"2",
"9",
"12",
"20",
"89",
"90",
"21",
"22",
"91",
"99",
"102",
"109"
] | [
"nonn",
"tabf",
"base"
] | 18 | 0 | 3 | [
"A381236",
"A381237"
] | null | N. J. A. Sloane, Mar 16 2025 | 2025-03-17T15:39:31 | oeisdata/seq/A381/A381236.seq | 66d4f50190887c06539dc0eb79d834ca |
A381237 | a(n) = sum of row n of A381236. | [
"0",
"1",
"11",
"11",
"11",
"11",
"11",
"11",
"11",
"11",
"11",
"11",
"222",
"111",
"222",
"222",
"111",
"222",
"222",
"111",
"222",
"444",
"444",
"222",
"222",
"111",
"222",
"222",
"111",
"222",
"222",
"444",
"222",
"444",
"222",
"222",
"222",
"37",
"222",
"222",
"222",
"444",
"444",
"444",
"444",
"222",
"111",
"222",
"222",
"111",
"222",
"444",
"444",
"222",
"444"
] | [
"nonn",
"base"
] | 14 | 0 | 3 | [
"A381236",
"A381237"
] | null | N. J. A. Sloane, Mar 16 2025 | 2025-03-17T15:33:22 | oeisdata/seq/A381/A381237.seq | bf5ae29b60d3800a969157417473bd73 |
A381238 | a(n) = floor(b(n)), where b(n) = sec^2(b(n-1)), b(0)=1. | [
"1",
"3",
"1",
"4",
"66",
"1",
"11",
"4",
"8",
"3",
"1",
"6",
"1",
"143",
"2",
"1",
"481",
"10",
"14",
"6",
"1",
"4",
"11",
"2",
"1",
"140",
"3",
"1",
"3",
"1",
"7",
"14",
"2",
"2",
"1",
"3",
"1",
"39",
"3",
"1",
"2159",
"3",
"1",
"4",
"3",
"1",
"3",
"1",
"14",
"10",
"1",
"11",
"6",
"1",
"3",
"1",
"4",
"185",
"1",
"3",
"1",
"4",
"78",
"1",
"3",
"1",
"6",
"1",
"4",
"3",
"2",
"2",
"1",
"11",
"17",
"8",
"15",
"1",
"16",
"5",
"1",
"14",
"4",
"8",
"7",
"1",
"20",
"7",
"96",
"14",
"62",
"1",
"3",
"2",
"2",
"1",
"91",
"1",
"10",
"97",
"1"
] | [
"nonn"
] | 17 | 0 | 2 | [
"A000319",
"A005699",
"A381238",
"A382148"
] | null | N. J. A. Sloane, Mar 17 2025 | 2025-03-18T12:57:09 | oeisdata/seq/A381/A381238.seq | 975913ff87d1be07370231c4171f7783 |
A381239 | Primes of the form Sum_{k >= 0} floor(m/5^k) for some number m. | [
"2",
"3",
"7",
"13",
"19",
"31",
"37",
"41",
"43",
"47",
"53",
"59",
"71",
"83",
"89",
"97",
"101",
"103",
"107",
"109",
"113",
"127",
"131",
"137",
"139",
"149",
"151",
"157",
"163",
"181",
"191",
"193",
"197",
"199",
"211",
"227",
"233",
"239",
"251",
"257",
"263",
"269",
"271",
"277",
"281",
"283",
"293",
"307",
"313",
"331",
"337",
"347",
"349",
"353",
"359"
] | [
"nonn"
] | 4 | 1 | 1 | [
"A191610",
"A380662",
"A381239"
] | null | Clark Kimberling, Mar 09 2025 | 2025-03-16T18:24:17 | oeisdata/seq/A381/A381239.seq | 82a57349db1fc4d0f6b0b1c330aa3036 |
A381240 | Indices of records in A381096. | [
"1",
"6",
"10",
"12",
"14",
"18",
"22",
"24",
"28",
"30",
"42",
"54",
"60",
"66",
"78",
"84",
"90",
"102",
"114",
"120",
"126",
"132",
"138",
"150",
"168",
"180",
"198",
"204",
"210",
"240",
"252",
"264",
"270",
"294",
"300",
"330",
"360",
"378",
"390",
"420",
"450",
"462",
"480",
"504",
"510",
"540",
"546",
"570",
"600",
"630",
"660",
"690",
"714",
"750",
"780",
"810",
"840"
] | [
"nonn"
] | 8 | 1 | 2 | [
"A000010",
"A005361",
"A024619",
"A381096",
"A381240",
"A381241"
] | null | Michael De Vlieger, Feb 18 2025 | 2025-02-25T11:41:00 | oeisdata/seq/A381/A381240.seq | 0b64b0a82d825cf2e4efd5aeea3276b7 |
A381241 | Records in A381096. | [
"0",
"3",
"5",
"6",
"7",
"10",
"11",
"13",
"14",
"21",
"29",
"33",
"42",
"45",
"53",
"58",
"64",
"69",
"77",
"85",
"88",
"90",
"93",
"108",
"117",
"128",
"136",
"138",
"161",
"172",
"176",
"181",
"195",
"208",
"216",
"249",
"258",
"267",
"293",
"322",
"326",
"341",
"347",
"354",
"381",
"390",
"401",
"425",
"434",
"484",
"498",
"513",
"521",
"547",
"586",
"590",
"645",
"652"
] | [
"nonn"
] | 5 | 1 | 2 | [
"A381096",
"A381240",
"A381241"
] | null | Michael De Vlieger, Feb 24 2025 | 2025-02-25T11:41:14 | oeisdata/seq/A381/A381241.seq | 0d93c8cb1f4c9815a6a19db090801d17 |
A381242 | Lexicographically earliest sequence of distinct terms > 1 such that no term is a substring of the product of any two terms. | [
"2",
"3",
"20",
"22",
"28",
"30",
"200",
"202",
"220",
"248",
"280",
"300",
"2000",
"2002",
"2020",
"2022",
"2200",
"2480",
"2800",
"3000",
"3252",
"3272",
"20000",
"20002",
"20020",
"20022",
"20200",
"20220",
"22000",
"23252",
"24800",
"28000",
"30000",
"32520",
"32720",
"200000",
"200002",
"200020",
"200022",
"200200",
"200202",
"200220"
] | [
"nonn",
"base"
] | 16 | 1 | 1 | [
"A381242",
"A382453"
] | null | Dominic McCarty, Mar 24 2025 | 2025-03-26T21:47:33 | oeisdata/seq/A381/A381242.seq | aee616f64e965c022889e1ffc49d7bda |
A381243 | Number of hyperplanes defined by the nonzero differences of two permutations of order n. | [
"0",
"0",
"1",
"6",
"85",
"1370",
"30481",
"778610",
"24409645",
"881325366",
"36635553601",
"1713454403210",
"89415912126223",
"5143372266050837",
"323667807885619744",
"22112062644980805684"
] | [
"nonn",
"more"
] | 10 | 0 | 4 | [
"A019589",
"A175176",
"A362968",
"A381243",
"A381244",
"A381339"
] | null | Max Alekseyev, Feb 17 2025 | 2025-02-24T04:17:57 | oeisdata/seq/A381/A381243.seq | 0faee9a63adc26046de351f162abecbd |
A381244 | Number of regions in the arrangement of hyperplanes corresponding to the nonzero differences of two permutations of order n. | [
"1",
"1",
"2",
"12",
"3696"
] | [
"nonn",
"more",
"hard"
] | 9 | 0 | 3 | [
"A019589",
"A175176",
"A362968",
"A381243",
"A381244"
] | null | Max Alekseyev, Feb 17 2025 | 2025-02-18T19:00:05 | oeisdata/seq/A381/A381244.seq | e63ce8bcc3d5adf48c19ae44ccfb8a27 |
A381245 | Numbers that are partial sums of the reverses of the sequence of primes and are reverses of primes. | [
"2",
"5",
"17",
"358",
"775",
"3145",
"7813",
"10277",
"13978",
"15232",
"19478",
"32324",
"36056",
"70042",
"71396",
"72893",
"76856",
"102374",
"141982",
"155585",
"301291",
"331357",
"332588",
"354643",
"717817",
"763586",
"791641",
"799532",
"922981",
"931705",
"935117",
"940241",
"952975",
"993551",
"1020461",
"1028383",
"1060075",
"1094099",
"1126831",
"1145257"
] | [
"nonn",
"base"
] | 8 | 1 | 1 | [
"A004087",
"A071602",
"A381245"
] | null | Robert Israel, Feb 17 2025 | 2025-02-18T18:50:39 | oeisdata/seq/A381/A381245.seq | f99151e61ef3452e65e48348bb8fd0ce |
A381247 | Positive integers m such that m * (m+1) contains at least 8 decimal digits that are in neither m nor m+1. | [
"77776",
"88888",
"444554",
"554544",
"655555",
"656565",
"656665",
"888787",
"888888",
"1111121",
"1212121",
"1222121",
"2212121",
"2222232",
"2222332",
"2223222",
"2232222",
"2322322",
"2332222",
"3223232",
"3223332",
"3232222",
"3233322",
"3322332",
"3323232",
"3443443",
"4334443",
"4343443",
"4444443",
"4544444",
"5444444",
"5445554",
"5455454"
] | [
"nonn",
"base"
] | 25 | 1 | 1 | [
"A381247",
"A381248"
] | null | Ali Sada and M. F. Hasler, Feb 17 2025 | 2025-02-19T10:21:00 | oeisdata/seq/A381/A381247.seq | 12c76e64b431b54f1d3a1c10c59d1429 |
A381248 | a(n) = least positive integer m such that m*(m+1) has n-2 distinct digits in base n, all distinct from those (base-n digits) of m and m+1. | [
"1",
"4",
"14",
"156",
"20",
"750",
"1763",
"22142",
"77776",
"64420",
"2443077",
"52663933",
"227623468",
"1097568095",
"3149642939",
"81965144711",
"105625962315",
"143416754568",
"8084207326294",
"2574579252942508",
"14079288482520493",
"68732231173154643",
"33344665050312525",
"350798169613138819009",
"201175550741393337488"
] | [
"nonn",
"base"
] | 33 | 2 | 2 | [
"A381247",
"A381248"
] | null | Ali Sada and M. F. Hasler, Feb 17 2025 | 2025-02-18T22:42:49 | oeisdata/seq/A381/A381248.seq | c9f370c52a61db371e023408c915a0a1 |
A381249 | Indices of records in k/A001414(k), k>=2. | [
"2",
"6",
"8",
"9",
"12",
"15",
"16",
"18",
"24",
"27",
"32",
"36",
"40",
"45",
"48",
"54",
"60",
"64",
"72",
"80",
"81",
"90",
"96",
"108",
"120",
"128",
"135",
"144",
"160",
"162",
"180",
"192",
"216",
"240",
"243",
"270",
"288",
"320",
"324",
"360",
"384",
"405",
"432",
"480",
"486",
"540",
"576",
"640",
"648",
"720",
"729",
"810",
"864",
"960",
"972",
"1024",
"1080",
"1152"
] | [
"nonn",
"new"
] | 14 | 1 | 1 | [
"A001414",
"A082299",
"A082343",
"A082344",
"A381249",
"A381972"
] | null | Clark Kimberling, Apr 19 2025 | 2025-04-27T14:54:02 | oeisdata/seq/A381/A381249.seq | 6548474b275b868fa421f59fc104b035 |
A381251 | a(n) is the number of ways to write prime(n) as a sum of distinct composites. | [
"0",
"0",
"0",
"0",
"0",
"1",
"1",
"3",
"4",
"10",
"14",
"27",
"40",
"52",
"74",
"133",
"229",
"276",
"457",
"626",
"744",
"1189",
"1599",
"2498",
"4450",
"5862",
"6752",
"8835",
"10139",
"13189",
"32481",
"41614",
"60099",
"67900",
"122825",
"138101",
"195147",
"274193",
"342783",
"477381",
"661502",
"736865",
"1252245",
"1390615",
"1711496",
"1897886"
] | [
"nonn",
"new"
] | 23 | 1 | 8 | [
"A000040",
"A002808",
"A053872",
"A071904",
"A204389",
"A381251",
"A383037"
] | null | Felix Huber, Apr 19 2025 | 2025-04-24T13:23:57 | oeisdata/seq/A381/A381251.seq | d3903df6dd1d8b91bdfc7e7abb30230f |
A381252 | Decimal expansion of the area of the biggest little octagon. | [
"7",
"2",
"6",
"8",
"6",
"8",
"4",
"8",
"2",
"7",
"5",
"1",
"6",
"2",
"6",
"7",
"6",
"6",
"8",
"3",
"8",
"1",
"8",
"6",
"5",
"3",
"8",
"1",
"0",
"3",
"5",
"5",
"9",
"2",
"0",
"3",
"7",
"5",
"1",
"7",
"2",
"2",
"1",
"2",
"1",
"6",
"0",
"8",
"8",
"3",
"8",
"5",
"4",
"0",
"6",
"4",
"9",
"9",
"3",
"8",
"9",
"0",
"5",
"6",
"4",
"7",
"6",
"1",
"5",
"0",
"0",
"6",
"8",
"3",
"3",
"7",
"8",
"6",
"2",
"3",
"3",
"3",
"4",
"0",
"2",
"8",
"3",
"0",
"8",
"7",
"9",
"1",
"6",
"1",
"5",
"0",
"4",
"6",
"8",
"5",
"3",
"9",
"5",
"0",
"9",
"8",
"8",
"2",
"4",
"5",
"2",
"4",
"3",
"5",
"7",
"8",
"6",
"6",
"7",
"5"
] | [
"nonn",
"cons",
"new"
] | 12 | 1 | 1 | [
"A111969",
"A381252",
"A383173"
] | null | Eric W. Weisstein, Apr 17 2025 | 2025-04-20T08:40:28 | oeisdata/seq/A381/A381252.seq | f9c5c69c433300023bca0b9d8c9599a0 |
A381255 | Positive integers not of the form round(2^(k+2)/5). Complement of A007910. | [
"4",
"5",
"7",
"8",
"9",
"10",
"11",
"12",
"14",
"15",
"16",
"17",
"18",
"19",
"20",
"21",
"22",
"23",
"24",
"25",
"27",
"28",
"29",
"30",
"31",
"32",
"33",
"34",
"35",
"36",
"37",
"38",
"39",
"40",
"41",
"42",
"43",
"44",
"45",
"46",
"47",
"48",
"49",
"50",
"52",
"53",
"54",
"55",
"56",
"57",
"58",
"59",
"60",
"61",
"62",
"63",
"64",
"65",
"66",
"67",
"68",
"69",
"70",
"71",
"72",
"73",
"74"
] | [
"nonn",
"new"
] | 12 | 1 | 1 | [
"A007910",
"A381255"
] | null | Chai Wah Wu, Apr 21 2025 | 2025-04-22T02:39:14 | oeisdata/seq/A381/A381255.seq | f18116f31c862bb844614cb4f75269b1 |
A381256 | Numbers k such that 5*k+1 divides 5^k+1. | [
"0",
"1",
"625",
"57057",
"7748433",
"30850281",
"111494625",
"393423745",
"499088601",
"519341361",
"1051107705",
"1329416385",
"1616038425",
"2215448001",
"2433936225",
"2852972265",
"3399207273",
"4344683849",
"4961725281",
"5454760185",
"5485530369",
"6578054145",
"6678031745",
"7701979761",
"7807302825"
] | [
"nonn"
] | 12 | 1 | 3 | [
"A222948",
"A224486",
"A230076",
"A381256",
"A381257",
"A381258"
] | null | René-Louis Clerc, Feb 18 2025 | 2025-03-08T20:22:57 | oeisdata/seq/A381/A381256.seq | 91f11073d91cd2bab5ecbfeee0da6d7f |
A381257 | Numbers k such that 6*k+1 divides 6^k+1. | [
"0",
"1",
"6",
"30",
"58",
"70",
"73",
"90",
"101",
"105",
"121",
"125",
"146",
"153",
"166",
"170",
"181",
"182",
"185",
"210",
"233",
"241",
"242",
"266",
"282",
"290",
"322",
"373",
"381",
"385",
"390",
"397",
"441",
"445",
"446",
"450",
"453",
"530",
"557",
"562",
"585",
"593",
"601",
"602",
"605",
"606",
"621",
"646",
"653",
"670",
"685",
"710",
"726",
"805",
"810",
"817",
"833",
"837",
"853",
"866"
] | [
"nonn"
] | 16 | 1 | 3 | [
"A222948",
"A224486",
"A230076",
"A381256",
"A381257",
"A381258"
] | null | René-Louis Clerc, Feb 18 2025 | 2025-04-02T20:58:20 | oeisdata/seq/A381/A381257.seq | ec028debef683e2646f562de1ed9eb4f |
A381258 | Numbers k such that 7*k+1 divides 7^k+1. | [
"0",
"1",
"135",
"5733",
"11229",
"42705",
"50445",
"117649",
"131365",
"168093",
"636405",
"699825",
"1269495",
"2528155",
"4226175",
"6176709",
"6502545",
"9365265",
"9551115",
"13227021",
"14464485",
"14912625",
"20859435",
"26903605",
"28251265",
"30589905",
"32660901",
"37597329",
"41506875",
"42766465",
"55452075",
"56192535",
"111898605"
] | [
"nonn"
] | 20 | 1 | 3 | [
"A222948",
"A224486",
"A230076",
"A381256",
"A381257",
"A381258"
] | null | René-Louis Clerc, Feb 18 2025 | 2025-03-05T12:06:33 | oeisdata/seq/A381/A381258.seq | c762b8d87894333dc6778bbcc4645579 |
A381259 | Numbers obtained by concatenating powers of 2, sorted into increasing order. | [
"1",
"2",
"4",
"8",
"11",
"12",
"14",
"16",
"18",
"21",
"22",
"24",
"28",
"32",
"41",
"42",
"44",
"48",
"64",
"81",
"82",
"84",
"88",
"111",
"112",
"114",
"116",
"118",
"121",
"122",
"124",
"128",
"132",
"141",
"142",
"144",
"148",
"161",
"162",
"164",
"168",
"181",
"182",
"184",
"188",
"211",
"212",
"214",
"216",
"218",
"221",
"222",
"224",
"228",
"232",
"241",
"242",
"244",
"248",
"256",
"264"
] | [
"nonn",
"base",
"easy"
] | 22 | 1 | 2 | [
"A000079",
"A028846",
"A045507",
"A152242",
"A178664",
"A381259"
] | null | Stefano Spezia, Feb 18 2025 | 2025-02-20T12:58:18 | oeisdata/seq/A381/A381259.seq | 5787ab8d622f4415740d446eb45a467f |
A381260 | Expansion of e.g.f. exp( -LambertW(-2 * x * cosh(x)) / 2 ). | [
"1",
"1",
"5",
"52",
"789",
"16116",
"415633",
"12963952",
"474761577",
"19974663568",
"949570545501",
"50341473508800",
"2944936306028797",
"188445333393978688",
"13094108333345047401",
"981850811606401705216",
"79025876659261666454481",
"6795576727642475440025856",
"621789675800920271144983477"
] | [
"nonn"
] | 8 | 0 | 3 | [
"A185951",
"A381140",
"A381260"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-18T08:57:17 | oeisdata/seq/A381/A381260.seq | ddbc71fab7791dea69a0c1601a2bb967 |
A381261 | Expansion of e.g.f. exp( -LambertW(-2 * x * cos(x)) / 2 ). | [
"1",
"1",
"5",
"46",
"669",
"13176",
"328153",
"9889328",
"349998169",
"14232282112",
"653960139021",
"33511444515968",
"1894938691013173",
"117209395966704640",
"7872535432641217185",
"570622024676568564736",
"44395462114163659522353",
"3690312836780077587120128",
"326399124496126009678138261"
] | [
"nonn"
] | 9 | 0 | 3 | [
"A185951",
"A381141",
"A381261"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-18T08:57:22 | oeisdata/seq/A381/A381261.seq | 08d903cac2e79ff2d03fc5ddc934cdc3 |
A381262 | Expansion of e.g.f. exp( -LambertW(-2 * sinh(x)) / 2 ). | [
"1",
"1",
"5",
"50",
"749",
"15132",
"385953",
"11907520",
"431376345",
"17954558928",
"844397935517",
"44287052219104",
"2563077440429701",
"162259043437047104",
"11154216390820950585",
"827464985582299977728",
"65889383717510410496689",
"5605511011776107945980160",
"507429545895353798767136181"
] | [
"nonn"
] | 9 | 0 | 3 | [
"A136630",
"A219503",
"A381262"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-18T08:57:27 | oeisdata/seq/A381/A381262.seq | d8c02d1a1ef7fc2bd438f76acc328ef2 |
A381263 | Expansion of e.g.f. exp( -LambertW(-2 * sin(x)) / 2 ). | [
"1",
"1",
"5",
"48",
"709",
"14152",
"356793",
"10882648",
"389790889",
"16040853568",
"745908722477",
"38681745244032",
"2213527304014189",
"138556837227204736",
"9417928265797994145",
"690818806495197538816",
"54391227913053881634001",
"4575388875753714015748096",
"409532433006878699321370197"
] | [
"nonn"
] | 8 | 0 | 3 | [
"A136630",
"A381142",
"A381263"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-18T08:57:33 | oeisdata/seq/A381/A381263.seq | 7c5e6e8f41bda079bdf18e68943a1025 |
A381264 | Decimal expansion of the edge length of the dodecahedron inside a circumscribed unit sphere. | [
"7",
"1",
"3",
"6",
"4",
"4",
"1",
"7",
"9",
"5",
"4",
"6",
"1",
"7",
"9",
"8",
"6",
"3",
"8",
"8",
"3",
"9",
"3",
"9",
"6",
"8",
"6",
"0",
"9",
"2",
"1",
"7",
"5",
"7",
"4",
"7",
"9",
"6",
"3",
"3",
"7",
"2",
"1",
"5",
"0",
"4",
"9",
"3",
"7",
"3",
"6",
"7",
"3",
"2",
"8",
"4",
"3",
"9",
"2",
"2",
"2",
"6",
"2",
"2",
"2",
"0",
"5",
"1",
"6",
"6",
"9",
"1",
"6",
"7",
"6",
"0",
"5",
"9",
"6",
"6",
"5",
"4",
"7",
"9",
"3",
"8",
"0",
"3",
"9",
"6",
"7",
"0"
] | [
"nonn",
"cons"
] | 21 | 0 | 1 | [
"A001622",
"A156547",
"A179296",
"A381264"
] | null | R. J. Mathar, Feb 18 2025 | 2025-02-26T02:13:08 | oeisdata/seq/A381/A381264.seq | 93e638349aada9f6db6634f4edd516e7 |
A381265 | a(n) is the number of solid (3D) partitions of n with 2 layers and second layer a plane partition of 3. | [
"6",
"21",
"57",
"138",
"294",
"606",
"1170",
"2208",
"4008",
"7176",
"12492",
"21510",
"36348",
"60801",
"100281",
"164019",
"265263",
"425853"
] | [
"nonn",
"more"
] | 8 | 3 | 1 | [
"A000041",
"A000219",
"A000990",
"A378854",
"A381265"
] | null | Wouter Meeussen, Feb 18 2025 | 2025-02-18T19:00:44 | oeisdata/seq/A381/A381265.seq | cafb92d5b02784f7d987931a425cfb99 |
A381266 | a(n) = least positive integer m such that when m*(m+1) is written in base n, it contains every single digit exactly once, or 0 if no such number exists. | [
"1",
"0",
"12",
"34",
"134",
"0",
"1477",
"6891",
"38627",
"0",
"891230",
"4874690",
"28507439",
"0",
"1078575795",
"7002987575",
"46916000817",
"0",
"2295911609450",
"16720559375850",
"124852897365573",
"0",
"7468470450367652",
"59705969514613035",
"487357094495846175",
"0",
"34452261762372201726",
"297930994005481958694"
] | [
"nonn",
"base"
] | 27 | 2 | 3 | [
"A381248",
"A381266"
] | null | Daniel Mondot and Ali Sada, Feb 18 2025 | 2025-03-17T22:15:51 | oeisdata/seq/A381/A381266.seq | f7bb48d2c0ef65b233942ff428391f69 |
A381267 | a(n) = numerator( [(x*y*z*u)^n] 1/sqrt(1 - (x + y + z + u*(y + z))) ). | [
"1",
"15",
"31185",
"6381375",
"409933148625",
"115551955934415",
"561860686475913825",
"179982394552964750175",
"245527483089290688069980625",
"84259935283701238220954169375",
"473788223464393905637179153328785",
"169752647693877043154936308907932575",
"15821279983229628402902553309640505635425"
] | [
"nonn",
"frac"
] | 10 | 0 | 2 | [
"A009971",
"A134375",
"A381267",
"A381268"
] | null | Stefano Spezia, Feb 18 2025 | 2025-02-19T13:37:44 | oeisdata/seq/A381/A381267.seq | 390b466c384f53d9d71cbf58745968f3 |
A381268 | a(n) = denominator( [(x*y*z*u)^n] 1/sqrt(1 - (x + y + z + u*(y + z))) ). | [
"1",
"4",
"256",
"1024",
"1048576",
"4194304",
"268435456",
"1073741824",
"17592186044416",
"70368744177664",
"4503599627370496",
"18014398509481984",
"18446744073709551616",
"73786976294838206464",
"4722366482869645213696",
"18889465931478580854784",
"4951760157141521099596496896",
"19807040628566084398385987584"
] | [
"nonn",
"frac"
] | 8 | 0 | 2 | [
"A009971",
"A134375",
"A278142",
"A381267",
"A381268"
] | null | Stefano Spezia, Feb 18 2025 | 2025-02-19T13:37:32 | oeisdata/seq/A381/A381268.seq | 94ba485fea6be037829ecc2156014463 |
A381269 | a(n) = numerator( [x*y*z]^n 1/sqrt((1 - (x + y + z))*(1 - y - z^2)) ). | [
"1",
"9",
"1695",
"26215",
"120986775",
"9502702209",
"789204625209",
"34080236440965",
"1551341154742525575",
"141040042903795882275",
"52208336916743049297255",
"306352374268280009960745",
"1862930539686953773794528225",
"178800539000323387892726124675",
"34618577499107880715911257143875"
] | [
"nonn",
"frac"
] | 10 | 0 | 2 | [
"A381269",
"A381270",
"A381271",
"A381272"
] | null | Stefano Spezia, Feb 18 2025 | 2025-02-19T13:37:24 | oeisdata/seq/A381/A381269.seq | f3cc8e1583004be9e19f1bb92d431288 |
A381270 | a(n) = denominator( [x*y*z]^n 1/sqrt((1 - (x + y + z))*(1 - y - z^2)) ). | [
"1",
"4",
"64",
"64",
"16384",
"65536",
"262144",
"524288",
"1073741824",
"4294967296",
"68719476736",
"17179869184",
"4398046511104",
"17592186044416",
"140737488355328",
"281474976710656",
"4611686018427387904",
"18446744073709551616",
"295147905179352825856",
"295147905179352825856",
"75557863725914323419136"
] | [
"nonn",
"frac"
] | 9 | 0 | 2 | [
"A381269",
"A381270",
"A381271",
"A381272"
] | null | Stefano Spezia, Feb 18 2025 | 2025-02-19T13:37:15 | oeisdata/seq/A381/A381270.seq | 74b540352b31b243d26d85d708fc3805 |
A381271 | a(n) = numerator( [x*y*z]^n 1/sqrt((1 - (x + y + z))*(1 - x - y - z^2)) ). | [
"1",
"3",
"195",
"665",
"820575",
"15306291",
"321221901",
"3400981155",
"38681474812695",
"872267067639825",
"80552172130705275",
"117735218601670215",
"178666542358192113225",
"4278458781930443466825",
"206819443902585382527375",
"2518237991059733983111695",
"252890952855692468573188869255",
"6236413379907980580174936458925",
"618385442772270188414534006897025"
] | [
"nonn",
"frac",
"changed"
] | 22 | 0 | 2 | [
"A381269",
"A381270",
"A381271",
"A381272"
] | null | Stefano Spezia, Feb 18 2025 | 2025-04-14T03:14:07 | oeisdata/seq/A381/A381271.seq | 00dea08b7f9e63d6fea58a18ccf05700 |
A381272 | a(n) = denominator( [x*y*z]^n 1/sqrt((1 - (x + y + z))*(1 - x - y - z^2)) ). | [
"1",
"1",
"4",
"1",
"64",
"64",
"64",
"32",
"16384",
"16384",
"65536",
"4096",
"262144",
"262144",
"524288",
"262144",
"1073741824",
"1073741824",
"4294967296",
"1073741824",
"68719476736",
"68719476736",
"17179869184",
"8589934592",
"4398046511104",
"4398046511104",
"17592186044416",
"2199023255552",
"140737488355328",
"140737488355328",
"281474976710656",
"140737488355328",
"4611686018427387904"
] | [
"nonn",
"frac",
"changed"
] | 23 | 0 | 3 | [
"A381269",
"A381270",
"A381271",
"A381272"
] | null | Stefano Spezia, Feb 18 2025 | 2025-04-14T03:15:02 | oeisdata/seq/A381/A381272.seq | 9eb8055f5a750cdfa6a2f58df641e088 |
A381273 | Expansion of e.g.f. exp(x * cosh(2*x)). | [
"1",
"1",
"1",
"13",
"49",
"201",
"2161",
"12629",
"102817",
"1118161",
"9109921",
"105660765",
"1223720785",
"13461561881",
"186666204817",
"2406325357861",
"33607592404033",
"516511765519521",
"7658010172957249",
"126206019752173997",
"2115466479287184241",
"36218229615683409001",
"666810643855970901937"
] | [
"sign"
] | 11 | 0 | 4 | [
"A003727",
"A185951",
"A381273",
"A381274"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:40:32 | oeisdata/seq/A381/A381273.seq | d7d288dbe4aace2cb7967612b4bf8982 |
A381274 | Expansion of e.g.f. exp(x * cosh(3*x)). | [
"1",
"1",
"1",
"28",
"109",
"676",
"10261",
"65584",
"881497",
"11930896",
"122708521",
"2186539840",
"30542901445",
"477545743936",
"9168255077437",
"149358238356736",
"3043023842477233",
"61000460650291456",
"1225825910880514129",
"28395625697194028032",
"621110654837608378141",
"14936817377079335166976"
] | [
"nonn"
] | 9 | 0 | 4 | [
"A003727",
"A185951",
"A381273",
"A381274"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:36:34 | oeisdata/seq/A381/A381274.seq | b15238cfbc160c2fd4d6b7a4632b6d75 |
A381275 | Expansion of e.g.f. exp(x * cos(2*x)). | [
"1",
"1",
"1",
"-11",
"-47",
"-39",
"1681",
"10893",
"-13215",
"-851471",
"-5515679",
"34375397",
"887687857",
"3982645577",
"-85350572943",
"-1466457337859",
"-659043831871",
"270733024430305",
"3181606182917569",
"-24432689736388395",
"-1076204061663657839",
"-6834631528147762247",
"221729710998069153617"
] | [
"sign"
] | 9 | 0 | 4 | [
"A009189",
"A185951",
"A381275",
"A381276"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:36:48 | oeisdata/seq/A381/A381275.seq | f5877d929fb66560e6b413f82a7acf01 |
A381276 | Expansion of e.g.f. exp(x * cos(3*x)). | [
"1",
"1",
"1",
"-26",
"-107",
"136",
"9181",
"53488",
"-427895",
"-10486016",
"-43859879",
"1373548672",
"23512856797",
"-30564574208",
"-6412871847563",
"-73709639926784",
"1060067525174929",
"40587133606543360",
"179320588932698929",
"-14474677657838059520",
"-306563699887974043739",
"2301792469199499132928"
] | [
"sign"
] | 12 | 0 | 4 | [
"A009189",
"A185951",
"A352643",
"A381275",
"A381276",
"A381283"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:37:08 | oeisdata/seq/A381/A381276.seq | f92720b6e47e3750d02dfd087c5b2010 |
A381277 | Expansion of e.g.f. exp(sinh(3*x) / 3). | [
"1",
"1",
"1",
"10",
"37",
"172",
"1477",
"8416",
"74377",
"683344",
"5836969",
"67102048",
"699721453",
"8268521536",
"107106298093",
"1347611617792",
"19462095444241",
"279380302430464",
"4247519795325649",
"68946703997616640",
"1122787065355425973",
"19697500164381137920",
"351304020205694058133"
] | [
"nonn"
] | 8 | 0 | 4 | [
"A003724",
"A009229",
"A136630",
"A381277"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:37:22 | oeisdata/seq/A381/A381277.seq | e50394064509b799518bde2f3518997a |
A381278 | Expansion of e.g.f. exp(sin(3*x) / 3). | [
"1",
"1",
"1",
"-8",
"-35",
"-8",
"1117",
"6328",
"-19943",
"-513728",
"-2096711",
"30574720",
"447401845",
"23791744",
"-59033858219",
"-527680180736",
"4971322421425",
"144677554315264",
"430091284739185",
"-27641200139694080",
"-398305237630617971",
"2876369985206861824",
"145441158283475935309"
] | [
"sign"
] | 10 | 0 | 4 | [
"A002017",
"A009210",
"A136630",
"A352640",
"A381278",
"A381286"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:37:37 | oeisdata/seq/A381/A381278.seq | 0277c5aef1bd8b2480bc69b4f3a24aee |
A381279 | a(1) = 1, for n > 1, a(n) = a(n - 1) / 2 if a(n - 1) is divisible by 2, otherwise a(n) = a(n - 1) + A000005(n - 1). | [
"1",
"2",
"1",
"3",
"6",
"3",
"7",
"9",
"13",
"16",
"8",
"4",
"2",
"1",
"5",
"9",
"14",
"7",
"13",
"15",
"21",
"25",
"29",
"31",
"39",
"42",
"21",
"25",
"31",
"33",
"41",
"43",
"49",
"53",
"57",
"61",
"70",
"35",
"39",
"43",
"51",
"53",
"61",
"63",
"69",
"75",
"79",
"81",
"91",
"94",
"47",
"51",
"57",
"59",
"67",
"71",
"79",
"83",
"87",
"89",
"101",
"103",
"107",
"113",
"120",
"60",
"30",
"15",
"21",
"25"
] | [
"nonn"
] | 22 | 1 | 2 | [
"A000005",
"A381279"
] | null | Ctibor O. Zizka, Apr 12 2025 | 2025-04-13T16:17:47 | oeisdata/seq/A381/A381279.seq | 297ad08f2458e5af1e4a96ade7701491 |
A381280 | Expansion of e.g.f. 1/(1 - x * cosh(2*x)). | [
"1",
"1",
"2",
"18",
"120",
"920",
"10320",
"126448",
"1714048",
"27073152",
"472354560",
"8989147904",
"187690331136",
"4245706716160",
"103239264593920",
"2691918892861440",
"74885151106498560",
"2212607133043884032",
"69227613551324233728",
"2286465386258267176960",
"79487593489348266557440"
] | [
"nonn",
"changed"
] | 12 | 0 | 3 | [
"A185951",
"A201939",
"A205571",
"A381280",
"A381281"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-04-19T07:16:15 | oeisdata/seq/A381/A381280.seq | f47950ad5b45682c74a4cb4d83f44911 |
A381281 | Expansion of e.g.f. 1/(1 - x * cosh(3*x)). | [
"1",
"1",
"2",
"33",
"240",
"2145",
"33120",
"480753",
"7878528",
"158696577",
"3384322560",
"78934776129",
"2053186983936",
"57231998680545",
"1714372871178240",
"55323775198258065",
"1899762412262031360",
"69264871449203672577",
"2677542944055160209408",
"109197154520146527569505"
] | [
"nonn"
] | 8 | 0 | 3 | [
"A185951",
"A205571",
"A381280",
"A381281"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:38:05 | oeisdata/seq/A381/A381281.seq | c3d19c287a55fdfa384e1e4bb1e64c41 |
A381282 | Expansion of e.g.f. 1/(1 - x * cos(2*x)). | [
"1",
"1",
"2",
"-6",
"-72",
"-520",
"-1200",
"24752",
"516992",
"5106816",
"5287680",
"-998945024",
"-23719719936",
"-272471972864",
"1326261594112",
"149170761246720",
"3843177252618240",
"42752553478356992",
"-863092250325614592",
"-59317347865870139392",
"-1577115871098630307840",
"-13173264127625587851264"
] | [
"sign"
] | 10 | 0 | 3 | [
"A185951",
"A352252",
"A381282",
"A381283"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:38:20 | oeisdata/seq/A381/A381282.seq | 68418cb99d80cf3ef4299707e24179ad |
A381283 | Expansion of e.g.f. 1/(1 - x * cos(3*x)). | [
"1",
"1",
"2",
"-21",
"-192",
"-1095",
"7200",
"243747",
"3088512",
"1360881",
"-874437120",
"-21701765349",
"-186175604736",
"5870711879721",
"292185085151232",
"5507319584787795",
"-38951106749890560",
"-6402114772676575263",
"-212680600451474522112",
"-1602903494245708491957",
"197042528380347210792960"
] | [
"sign"
] | 11 | 0 | 3 | [
"A185951",
"A352252",
"A381282",
"A381283"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:38:33 | oeisdata/seq/A381/A381283.seq | 56cfe0b066a67d9262f5e4e761d2437e |
A381284 | Expansion of e.g.f. 1/(1 - sinh(3*x) / 3). | [
"1",
"1",
"2",
"15",
"96",
"741",
"7632",
"87795",
"1149696",
"17155881",
"282880512",
"5128464375",
"101592631296",
"2178698451021",
"50314379323392",
"1245198047833755",
"32868161979088896",
"921803465256094161",
"27373850876851126272",
"858044392807801699935",
"28311289100161039466496"
] | [
"nonn",
"changed"
] | 10 | 0 | 3 | [
"A006154",
"A136630",
"A191277",
"A381284"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-04-19T06:00:02 | oeisdata/seq/A381/A381284.seq | 9d740fa8941fb2fd27462015ce2b839e |
A381285 | Expansion of e.g.f. 1/(1 - sin(2*x) / 2). | [
"1",
"1",
"2",
"2",
"-8",
"-104",
"-688",
"-3088",
"-128",
"209536",
"3145472",
"29795072",
"139389952",
"-1715047424",
"-60056147968",
"-1004215072768",
"-10305404960768",
"-1945682345984",
"2949643589844992",
"84438462955323392",
"1458284922371571712",
"12032890515685113856",
"-245515800089314459648"
] | [
"sign"
] | 9 | 0 | 3 | [
"A000111",
"A136630",
"A381285",
"A381286"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:38:57 | oeisdata/seq/A381/A381285.seq | 55b3275dea7330166c4d83d2b3ae589c |
A381286 | Expansion of e.g.f. 1/(1 - sin(3*x) / 3). | [
"1",
"1",
"2",
"-3",
"-48",
"-339",
"-1008",
"10737",
"237312",
"2362041",
"5432832",
"-318158523",
"-7615254528",
"-87216236379",
"173049219072",
"33959321252217",
"851545449234432",
"9561733579228401",
"-129701862228492288",
"-9445723672920941043",
"-239815723596207095808",
"-2109465061216228379619"
] | [
"sign"
] | 12 | 0 | 3 | [
"A000111",
"A136630",
"A352638",
"A381278",
"A381285",
"A381286"
] | null | Seiichi Manyama, Feb 18 2025 | 2025-02-19T03:39:09 | oeisdata/seq/A381/A381286.seq | b524b96948384be5f38584c754db3e32 |
A381287 | a(n) is the smallest nonnegative number congruent to k modulo prime(k)^(n-k+1) for k=1..n. | [
"1",
"5",
"353",
"65153",
"119966753",
"3050486978753",
"563678198162618753",
"15413934869729743026218753",
"1710386933322832904060816574218753",
"14712401204424400291787297607394206774218753",
"5027982881016562571248237683551040219315980699574218753",
"5488604004979149030407333271782173318791620565366546226763574218753"
] | [
"nonn"
] | 34 | 1 | 2 | [
"A005687",
"A006939",
"A381287"
] | null | Steven Lu, Feb 19 2025 | 2025-03-15T04:23:18 | oeisdata/seq/A381/A381287.seq | 7970c3616ff48711544bc2ffc4bf69ee |
A381288 | Partial alternating sums of the trajectory of 2 under the morphism 2->{2,1,2}, 1->{2}. | [
"0",
"2",
"1",
"3",
"1",
"3",
"2",
"4",
"2",
"3",
"1",
"3",
"2",
"4",
"2",
"4",
"3",
"5",
"3",
"4",
"2",
"4",
"2",
"3",
"1",
"3",
"2",
"4",
"2",
"4",
"3",
"5",
"3",
"4",
"2",
"4",
"3",
"5",
"3",
"5",
"4",
"6",
"4",
"5",
"3",
"5",
"3",
"4",
"2",
"4",
"3",
"5",
"3",
"4",
"2",
"4",
"2",
"3",
"1",
"3",
"2",
"4",
"2",
"4",
"3",
"5",
"3",
"4",
"2",
"4",
"3",
"5",
"3",
"5",
"4",
"6",
"4",
"5",
"3",
"5",
"3",
"4",
"2",
"4",
"3",
"5",
"3"
] | [
"nonn",
"easy"
] | 44 | 0 | 2 | [
"A001333",
"A104521",
"A106035",
"A381288"
] | null | Keith J. Bauer, Apr 01 2025 | 2025-04-02T15:09:52 | oeisdata/seq/A381/A381288.seq | a88ee451e7ac7468d0271721b50f923a |
A381289 | Number of subsets of 6 integers between 1 and n such that their sum is 0 modulo n. | [
"1",
"3",
"10",
"20",
"42",
"76",
"132",
"212",
"335",
"497",
"728",
"1028",
"1428",
"1932",
"2586",
"3384",
"4389",
"5601",
"7084",
"8844",
"10966",
"13442",
"16380",
"19780",
"23751",
"28301",
"33566",
"39536",
"46376",
"54086",
"62832",
"72624",
"83661",
"95931",
"109668",
"124872",
"141778",
"160398",
"181006"
] | [
"nonn",
"easy"
] | 35 | 7 | 2 | [
"A011796",
"A381289"
] | null | Xavier Roulleau and David Broadhurst, Feb 19 2025 | 2025-02-28T07:45:37 | oeisdata/seq/A381/A381289.seq | 3b9953e072ca0dd9cf62ae49acebb3f5 |
A381290 | Number of subsets of 6 integers between 1 and n such that their sum is 1 modulo n. | [
"1",
"4",
"9",
"22",
"42",
"78",
"132",
"217",
"333",
"504",
"728",
"1035",
"1428",
"1944",
"2583",
"3399",
"4389",
"5616",
"7084",
"8866",
"10962",
"13468",
"16380",
"19806",
"23751",
"28336",
"33561",
"39576",
"46376",
"54126",
"62832",
"72675",
"83655",
"95988",
"109668",
"124929",
"141778",
"160468",
"180999"
] | [
"nonn",
"easy"
] | 22 | 7 | 2 | [
"A011796",
"A381289",
"A381290"
] | null | Xavier Roulleau and David Broadhurst, Feb 19 2025 | 2025-02-28T07:45:46 | oeisdata/seq/A381/A381290.seq | ed0a2622e99aa1755ae0efc72f6578ed |
A381291 | Number of subsets of 8 integers between 1 and n such that their sum is 0 modulo n. | [
"1",
"5",
"15",
"43",
"99",
"217",
"429",
"809",
"1430",
"2438",
"3978",
"6310",
"9690",
"14550",
"21318",
"30666",
"43263",
"60115",
"82225",
"111041",
"148005",
"195143",
"254475",
"328755",
"420732",
"534076",
"672452",
"840652",
"1043460",
"1287036",
"1577532",
"1922740",
"2330445",
"2810385",
"3372291",
"4028183",
"4790071"
] | [
"nonn"
] | 22 | 9 | 2 | [
"A011796",
"A381289",
"A381290",
"A381291"
] | null | Xavier Roulleau and David Broadhurst, Feb 19 2025 | 2025-02-28T07:45:41 | oeisdata/seq/A381/A381291.seq | 1c71981d13bdf8bac2f049b71a14334f |
A381292 | Expansion of g.f. hypergeom([1/2, 3/4, 5/4], [1, 3/2], 256*x). | [
"1",
"80",
"12096",
"2196480",
"435635200",
"91017658368",
"19681596211200",
"4361120388218880",
"984138122900275200",
"225245492144504832000",
"52138539404512009912320",
"12180522019129546663526400",
"2867511425916768698757021696",
"679455041354637369514813030400",
"161892954188496214335204360192000"
] | [
"nonn"
] | 8 | 0 | 2 | [
"A001044",
"A277757",
"A381292"
] | null | Stefano Spezia, Feb 19 2025 | 2025-02-19T16:12:50 | oeisdata/seq/A381/A381292.seq | 9d19a36532e9de41bfac5ff4649343c7 |
A381293 | a(n) is the least prime p such that the number of primes between p (not inclusive) and p+n*log(p) is n. | [
"11",
"37",
"37",
"59",
"59",
"59",
"79",
"79",
"71",
"67",
"67",
"179",
"137",
"131",
"127",
"227",
"223",
"191",
"347",
"349",
"349",
"337",
"331",
"331",
"347",
"347",
"347",
"307",
"557",
"557",
"431",
"557",
"557",
"547",
"541",
"547",
"541",
"431",
"811",
"797",
"569",
"821",
"809",
"811",
"797",
"797",
"797",
"797",
"797",
"797"
] | [
"nonn"
] | 8 | 1 | 1 | null | null | Alain Rocchelli, Feb 19 2025 | 2025-03-05T19:02:20 | oeisdata/seq/A381/A381293.seq | 886ad5952996981da21ef6c060589d7f |
A381294 | Smallest number k such that there are n sets A_1,...,A_n with each A_i being a subset of {1,...,k} and the intersection of A_i and A_j has size |i-j| for all 1 <= i < j <= n. | [
"0",
"0",
"1",
"2",
"5",
"9",
"16",
"24",
"36",
"50",
"70",
"91",
"120",
"150",
"189",
"231",
"280",
"336",
"398",
"468",
"547",
"630",
"728"
] | [
"nonn",
"more"
] | 18 | 0 | 4 | null | null | Jonas Seiler, Feb 19 2025 | 2025-03-06T14:42:06 | oeisdata/seq/A381/A381294.seq | 5a7f7da375241ca4135a6518e092bdbb |
A381295 | a(n) = numerator( [(x*y*z*u*v)^n] 1/sqrt(1 - (x + y + z + u + v*(x*y*z + x*y*u + x*z*u + y*z*u))) ). | [
"1",
"3",
"735",
"1155",
"152927775",
"5729606883",
"944642139441",
"20804764619925",
"31532612849128108575",
"1514216480447305259625",
"1198479499879816971151335",
"15183210867901962855773895",
"200941692389810767447918272225",
"10564290945275296828332253777425",
"4507504507128763568843859426010875"
] | [
"nonn",
"frac"
] | 8 | 0 | 2 | [
"A381295",
"A381296"
] | null | Stefano Spezia, Feb 19 2025 | 2025-02-20T08:37:36 | oeisdata/seq/A381/A381295.seq | 9215410b8174a050d84f4e27f2ff5c81 |
A381296 | a(n) = denominator( [(x*y*z*u*v)^n] 1/sqrt(1 - (x + y + z + u + v*(x*y*z + x*y*u + x*z*u + y*z*u))) ). | [
"1",
"1",
"16",
"1",
"4096",
"4096",
"16384",
"8192",
"268435456",
"268435456",
"4294967296",
"1073741824",
"274877906944",
"274877906944",
"2199023255552",
"1099511627776",
"1152921504606846976",
"1152921504606846976",
"18446744073709551616",
"2305843009213693952",
"4722366482869645213696",
"4722366482869645213696"
] | [
"nonn",
"frac"
] | 7 | 0 | 3 | [
"A381295",
"A381296"
] | null | Stefano Spezia, Feb 19 2025 | 2025-02-20T08:37:40 | oeisdata/seq/A381/A381296.seq | 9feacef023bd175c826dba02dbb58018 |
A381297 | a(n) = numerator( [x^n] hypergeom([1/2, 1/2, 1/2, 1/4, 3/4], [1, 1, 1, 1], 256*x) ). | [
"1",
"6",
"2835",
"144375",
"9656521875",
"727613515629",
"1924950961452519",
"169849119537100575",
"515343459815505282121875",
"49523686986654845229890625",
"156852007784587147805477109405",
"15901454576103641443903862431665",
"1683931647757461343713885153275036775",
"177089976268148398718338641838887890625"
] | [
"nonn",
"frac"
] | 9 | 0 | 2 | [
"A381297",
"A381298"
] | null | Stefano Spezia, Feb 19 2025 | 2025-02-20T08:37:44 | oeisdata/seq/A381/A381297.seq | c5c0aa2de4f892bf777e66eaff5b501b |
A381298 | a(n) = denominator( [x^n] hypergeom([1/2, 1/2, 1/2, 1/4, 3/4], [1, 1, 1, 1], 256*x) ). | [
"1",
"1",
"8",
"4",
"2048",
"1024",
"16384",
"8192",
"134217728",
"67108864",
"1073741824",
"536870912",
"274877906944",
"137438953472",
"2199023255552",
"1099511627776",
"576460752303423488",
"288230376151711744",
"4611686018427387904",
"2305843009213693952",
"1180591620717411303424",
"590295810358705651712",
"9444732965739290427392"
] | [
"nonn",
"frac"
] | 7 | 0 | 3 | [
"A381297",
"A381298"
] | null | Stefano Spezia, Feb 19 2025 | 2025-02-20T08:37:48 | oeisdata/seq/A381/A381298.seq | 4e1cf7999d12297515344911df967785 |
A381299 | Irregular triangular array read by rows. T(n,k) is the number of ordered set partitions of [n] with exactly k descents, n>=0, 0<=k<=binomial(n,2). | [
"1",
"1",
"2",
"1",
"4",
"4",
"4",
"1",
"8",
"12",
"18",
"18",
"12",
"6",
"1",
"16",
"32",
"60",
"84",
"100",
"92",
"76",
"48",
"24",
"8",
"1",
"32",
"80",
"176",
"300",
"448",
"572",
"650",
"658",
"596",
"478",
"334",
"206",
"102",
"40",
"10",
"1",
"64",
"192",
"480",
"944",
"1632",
"2476",
"3428",
"4300",
"5008",
"5372",
"5356",
"4936",
"4220",
"3316",
"2392",
"1556",
"904",
"456",
"188",
"60",
"12",
"1"
] | [
"nonn",
"tabf"
] | 38 | 0 | 3 | [
"A000670",
"A001787",
"A008302",
"A011782",
"A125810",
"A161680",
"A240796",
"A268586",
"A289545",
"A347841",
"A347842",
"A347843",
"A347844",
"A347845",
"A347846",
"A381299"
] | null | Geoffrey Critzer, Feb 19 2025 | 2025-04-02T04:13:15 | oeisdata/seq/A381/A381299.seq | 1fca4c5248ebfb26732e30d28c718bbb |
A381300 | E.g.f. A(x) satisfies A(x) = 1/( 1 - x * cosh(x * A(x)^(1/2)) ). | [
"1",
"1",
"2",
"9",
"60",
"485",
"4800",
"57547",
"804160",
"12783969",
"228447360",
"4539156941",
"99244045824",
"2367795157741",
"61230675251200",
"1706241143585175",
"50971847057326080",
"1625178125581055297",
"55087299146009640960",
"1978201530490562626609",
"75025096312729021972480"
] | [
"nonn"
] | 8 | 0 | 3 | [
"A185951",
"A381300"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:24 | oeisdata/seq/A381/A381300.seq | 0dba0085ac9d79ffdeefd5f8dcd0b87a |
A381301 | E.g.f. A(x) satisfies A(x) = 1/( 1 - x * cos(x * A(x)^(1/2)) / A(x) ). | [
"1",
"1",
"0",
"-3",
"-12",
"5",
"240",
"1463",
"-2688",
"-92223",
"-662400",
"3249169",
"98672640",
"733006573",
"-7901816832",
"-224782617165",
"-1546734551040",
"34327512843137",
"929724626829312",
"5081202564853445",
"-243237724194078720",
"-6276196972896490059",
"-18788298569495347200",
"2624677015793433809647"
] | [
"sign"
] | 9 | 0 | 4 | [
"A185951",
"A381301"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:28 | oeisdata/seq/A381/A381301.seq | b280a811edeee1157df824b6026c1da3 |
A381302 | E.g.f. A(x) satisfies A(x) = 1/( 1 - x * cos(x * A(x)^(1/2)) ). | [
"1",
"1",
"2",
"3",
"-12",
"-235",
"-2400",
"-18067",
"-51520",
"1701009",
"49829760",
"872355319",
"9861874176",
"-8805084275",
"-4518287900672",
"-159719520182055",
"-3608706518138880",
"-44358720138978463",
"748112236681789440",
"72503399560668659531",
"2875934090148742430720",
"73418478070342765464741"
] | [
"sign"
] | 9 | 0 | 3 | [
"A185951",
"A381302"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:31 | oeisdata/seq/A381/A381302.seq | 7753f2f348400270d4b459b96253365d |
A381303 | E.g.f. A(x) satisfies A(x) = 1/( 1 - sinh(x * A(x)^(1/2)) / A(x)^(3/2) ). | [
"1",
"1",
"0",
"1",
"4",
"1",
"32",
"183",
"192",
"4921",
"33664",
"88573",
"2100224",
"16487745",
"83890176",
"1920800731",
"17243373568",
"143156073841",
"3236025171968",
"33490813489497",
"401094916964352",
"9092346624868321",
"109434837281013760",
"1724106500663768191",
"39706910863092875264"
] | [
"nonn"
] | 7 | 0 | 5 | [
"A136630",
"A381303"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:35 | oeisdata/seq/A381/A381303.seq | 675b4b753f2cefbec1fa58b77c81ff3b |
A381304 | E.g.f. A(x) satisfies A(x) = 1/( 1 - sinh(x * A(x)^(1/2)) / A(x)^(1/2) ). | [
"1",
"1",
"2",
"7",
"36",
"241",
"1984",
"19461",
"222080",
"2892361",
"42350976",
"688911763",
"12329035264",
"240789209025",
"5096898326528",
"116247332597833",
"2842225449025536",
"74165478671163601",
"2057366115038003200",
"60461340544432547391",
"1876511245926278365184",
"61336532673286072390321"
] | [
"nonn"
] | 7 | 0 | 3 | [
"A136630",
"A381304"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:38 | oeisdata/seq/A381/A381304.seq | 5b39c3dcab735002fe19c38a89dfe25a |
A381305 | E.g.f. A(x) satisfies A(x) = 1/( 1 - sin(x * A(x)^(1/2)) / A(x)^(3/2) ). | [
"1",
"1",
"0",
"-1",
"-4",
"1",
"32",
"181",
"-192",
"-4919",
"-31616",
"88571",
"2089984",
"13830545",
"-83841024",
"-1884928471",
"-11874992128",
"142704083281",
"3085703610368",
"16806597846295",
"-397246640947200",
"-8257973126103359",
"-32717082633175040",
"1686557057210338589",
"33490001971564773376"
] | [
"sign"
] | 8 | 0 | 5 | [
"A136630",
"A381305"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:42 | oeisdata/seq/A381/A381305.seq | 0e93051b969f966a1041ddbdc683a6e2 |
A381306 | E.g.f. A(x) satisfies A(x) = 1/( 1 - sin(x * A(x)^(1/2)) / A(x)^(1/2) ). | [
"1",
"1",
"2",
"5",
"12",
"1",
"-416",
"-5741",
"-60800",
"-543719",
"-3479424",
"6260561",
"822338048",
"20933340065",
"393396789248",
"5840683299431",
"54344509046784",
"-481407806103119",
"-44548560374988800",
"-1564969488082711811",
"-40856692743724335104",
"-812774967576805701599",
"-8614414458975040831488"
] | [
"sign"
] | 9 | 0 | 3 | [
"A136630",
"A381306"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:45 | oeisdata/seq/A381/A381306.seq | fdb3a35f32db00e731f6c45d85d36042 |
A381307 | E.g.f. A(x) satisfies A(x) = exp( x * cosh(x * A(x)^(1/2)) ). | [
"1",
"1",
"1",
"4",
"25",
"126",
"841",
"8303",
"84561",
"925480",
"12285121",
"181409427",
"2840445169",
"49113986936",
"932675641353",
"18883732449871",
"408771283327969",
"9499097097870720",
"234457146543484225",
"6115077874320445715",
"168654204908597822241",
"4902220448616467300248"
] | [
"nonn"
] | 8 | 0 | 4 | [
"A185951",
"A381307"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:50 | oeisdata/seq/A381/A381307.seq | 3cb24da6f1e633e56abaaac1aa05b014 |
A381308 | E.g.f. A(x) satisfies A(x) = exp( x * cos(x * A(x)^(1/2)) ). | [
"1",
"1",
"1",
"-2",
"-23",
"-114",
"-119",
"4929",
"66641",
"401320",
"-2429759",
"-103879555",
"-1429782287",
"-4427416408",
"296377270281",
"8315367151441",
"97844494408673",
"-912681931321984",
"-72768121697555135",
"-1687481800538833683",
"-9411056136574319839",
"820910149460546108776"
] | [
"sign"
] | 9 | 0 | 4 | [
"A185951",
"A381308"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:54 | oeisdata/seq/A381/A381308.seq | 3269979e7ced3770224959260fca27e7 |
A381309 | E.g.f. A(x) satisfies A(x) = exp( sinh(x * A(x)^(1/2)) / A(x)^(1/2) ). | [
"1",
"1",
"1",
"2",
"9",
"42",
"209",
"1381",
"11121",
"96744",
"936337",
"10323865",
"125245457",
"1640739336",
"23339285601",
"359236548033",
"5918755368865",
"103922094286976",
"1941594484205793",
"38448924176712705",
"803753373207738337",
"17693469280066921736",
"409266060724837855057",
"9922356658347766201841"
] | [
"nonn"
] | 8 | 0 | 4 | [
"A136630",
"A381309"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:39:58 | oeisdata/seq/A381/A381309.seq | ed9bc7a897edc5fdad5f23770b3325a4 |
A381310 | E.g.f. A(x) satisfies A(x) = exp( sin(x * A(x)^(1/2)) / A(x)^(1/2) ). | [
"1",
"1",
"1",
"0",
"-7",
"-38",
"-111",
"259",
"7025",
"59752",
"209297",
"-2545257",
"-59541487",
"-609139048",
"-1257456543",
"86370090271",
"1968628674465",
"20998208227456",
"-60103780767519",
"-7806917233342465",
"-175430347192682527",
"-1683391495632464904",
"26661441929560502097",
"1550891419460475900175"
] | [
"sign"
] | 8 | 0 | 5 | [
"A136630",
"A381310"
] | null | Seiichi Manyama, Feb 19 2025 | 2025-02-20T08:40:02 | oeisdata/seq/A381/A381310.seq | c6fc2d4e6aa0a4177a88aae4c8ffbf48 |
A381311 | Numbers whose powerful part (A057521) is a power of a prime with an even exponent >= 2. | [
"4",
"9",
"12",
"16",
"18",
"20",
"25",
"28",
"44",
"45",
"48",
"49",
"50",
"52",
"60",
"63",
"64",
"68",
"75",
"76",
"80",
"81",
"84",
"90",
"92",
"98",
"99",
"112",
"116",
"117",
"121",
"124",
"126",
"132",
"140",
"147",
"148",
"150",
"153",
"156",
"162",
"164",
"169",
"171",
"172",
"175",
"176",
"188",
"192",
"198",
"204",
"207",
"208",
"212",
"220",
"228",
"234",
"236"
] | [
"nonn",
"easy"
] | 12 | 1 | 1 | [
"A001248",
"A030514",
"A030516",
"A030629",
"A030631",
"A054753",
"A056798",
"A057521",
"A085987",
"A118914",
"A178739",
"A179644",
"A179645",
"A179668",
"A179672",
"A179693",
"A179747",
"A189982",
"A189983",
"A189985",
"A189987",
"A190110",
"A190292",
"A190388",
"A190641",
"A246655",
"A350388",
"A377816",
"A381311",
"A381312"
] | null | Amiram Eldar, Feb 19 2025 | 2025-02-21T08:23:47 | oeisdata/seq/A381/A381311.seq | 414ba6a421900891fcb483b701f8a84b |
A381312 | Numbers whose powerful part (A057521) is a power of a prime with an odd exponent >= 3 (A056824). | [
"8",
"24",
"27",
"32",
"40",
"54",
"56",
"88",
"96",
"104",
"120",
"125",
"128",
"135",
"136",
"152",
"160",
"168",
"184",
"189",
"224",
"232",
"243",
"248",
"250",
"264",
"270",
"280",
"296",
"297",
"312",
"328",
"343",
"344",
"351",
"352",
"375",
"376",
"378",
"384",
"408",
"416",
"424",
"440",
"456",
"459",
"472",
"480",
"486",
"488",
"512",
"513",
"520",
"536",
"544"
] | [
"nonn",
"easy"
] | 13 | 1 | 1 | [
"A030078",
"A050997",
"A056824",
"A057521",
"A065036",
"A079395",
"A092759",
"A118914",
"A138031",
"A178740",
"A179664",
"A179665",
"A179667",
"A179670",
"A179692",
"A179696",
"A179704",
"A189975",
"A189984",
"A190378",
"A190383",
"A190473",
"A190641",
"A268335",
"A301517",
"A374459",
"A381311",
"A381312"
] | null | Amiram Eldar, Feb 19 2025 | 2025-02-21T08:23:56 | oeisdata/seq/A381/A381312.seq | d79383f8e0ac0d9568320e838776aa05 |
A381313 | Numbers that are divisible by the cube of an odd prime. | [
"27",
"54",
"81",
"108",
"125",
"135",
"162",
"189",
"216",
"243",
"250",
"270",
"297",
"324",
"343",
"351",
"375",
"378",
"405",
"432",
"459",
"486",
"500",
"513",
"540",
"567",
"594",
"621",
"625",
"648",
"675",
"686",
"702",
"729",
"750",
"756",
"783",
"810",
"837",
"864",
"875",
"891",
"918",
"945",
"972",
"999",
"1000",
"1026",
"1029",
"1053",
"1080",
"1107",
"1125"
] | [
"nonn",
"easy"
] | 8 | 1 | 1 | [
"A000265",
"A002117",
"A038838",
"A046099",
"A233091",
"A381313"
] | null | Amiram Eldar, Feb 19 2025 | 2025-02-21T08:13:27 | oeisdata/seq/A381/A381313.seq | 3d7546f34cc58746b269d2582cf66312 |
A381314 | Powerful numbers that have a single exponent in their prime factorization that equals 2. | [
"4",
"9",
"25",
"49",
"72",
"108",
"121",
"144",
"169",
"200",
"288",
"289",
"324",
"361",
"392",
"400",
"500",
"529",
"576",
"675",
"784",
"800",
"841",
"961",
"968",
"972",
"1125",
"1152",
"1323",
"1352",
"1369",
"1372",
"1568",
"1600",
"1681",
"1849",
"1936",
"2025",
"2209",
"2304",
"2312",
"2500",
"2704",
"2809",
"2888",
"2916",
"3087",
"3136",
"3200"
] | [
"nonn",
"easy"
] | 8 | 1 | 1 | [
"A001248",
"A001694",
"A036966",
"A065483",
"A143610",
"A179646",
"A179689",
"A179699",
"A189988",
"A189990",
"A190106",
"A190115",
"A190470",
"A190471",
"A377816",
"A377818",
"A381314"
] | null | Amiram Eldar, Feb 19 2025 | 2025-02-21T08:15:26 | oeisdata/seq/A381/A381314.seq | 61eec94cff6f3c3d1146b4eb7a8cd714 |
A381315 | Numbers whose prime factorization exponents include exactly one 3 and no exponent greater than 3. | [
"8",
"24",
"27",
"40",
"54",
"56",
"72",
"88",
"104",
"108",
"120",
"125",
"135",
"136",
"152",
"168",
"184",
"189",
"200",
"232",
"248",
"250",
"264",
"270",
"280",
"296",
"297",
"312",
"328",
"343",
"344",
"351",
"360",
"375",
"376",
"378",
"392",
"408",
"424",
"440",
"456",
"459",
"472",
"488",
"500",
"504",
"513",
"520",
"536",
"540",
"552",
"568",
"584",
"594"
] | [
"nonn",
"easy"
] | 7 | 1 | 1 | [
"A002117",
"A030078",
"A046100",
"A048109",
"A065036",
"A143610",
"A163569",
"A176297",
"A179670",
"A179695",
"A179700",
"A189975",
"A189984",
"A190109",
"A190378",
"A190382",
"A375072",
"A375145",
"A381315"
] | null | Amiram Eldar, Feb 19 2025 | 2025-02-21T08:16:49 | oeisdata/seq/A381/A381315.seq | a3e1a0a9c76a2bb7546bbb7e2371f578 |
A381316 | Numbers whose powerful part (A057521) is a power of a prime with an exponent >= 3 (A246549). | [
"8",
"16",
"24",
"27",
"32",
"40",
"48",
"54",
"56",
"64",
"80",
"81",
"88",
"96",
"104",
"112",
"120",
"125",
"128",
"135",
"136",
"152",
"160",
"162",
"168",
"176",
"184",
"189",
"192",
"208",
"224",
"232",
"240",
"243",
"248",
"250",
"256",
"264",
"270",
"272",
"280",
"296",
"297",
"304",
"312",
"320",
"328",
"336",
"343",
"344",
"351",
"352",
"368",
"375",
"376",
"378"
] | [
"nonn",
"easy"
] | 10 | 1 | 1 | [
"A013661",
"A030078",
"A030514",
"A030516",
"A030629",
"A030631",
"A050997",
"A056824",
"A057521",
"A060687",
"A065036",
"A079395",
"A092759",
"A138031",
"A178739",
"A178740",
"A179644",
"A179645",
"A179664",
"A179665",
"A179667",
"A179668",
"A179670",
"A179672",
"A179692",
"A179693",
"A179696",
"A179704",
"A179747",
"A189975",
"A189984",
"A189987",
"A190110",
"A190292",
"A190378",
"A190383",
"A190388",
"A190473",
"A190641",
"A246549",
"A344653",
"A345193",
"A369632",
"A381312",
"A381316"
] | null | Amiram Eldar, Feb 19 2025 | 2025-02-21T08:24:05 | oeisdata/seq/A381/A381316.seq | 4c81370764a5991ebb857fa74b7659ac |
A381317 | Numbers of the form p^(p +- 1), where p is prime. | [
"2",
"8",
"9",
"81",
"625",
"15625",
"117649",
"5764801",
"25937424601",
"3138428376721",
"23298085122481",
"3937376385699289",
"48661191875666868481",
"14063084452067724991009",
"104127350297911241532841",
"37589973457545958193355601",
"907846434775996175406740561329",
"480250763996501976790165756943041"
] | [
"nonn",
"easy"
] | 9 | 1 | 1 | [
"A036878",
"A104126",
"A381215",
"A381317"
] | null | Paolo Xausa, Feb 20 2025 | 2025-02-21T06:10:28 | oeisdata/seq/A381/A381317.seq | 8a593d4b7b8fd9fe2aa2f438f7a8110c |
A381319 | Order of linear recurrence with constant coefficients of solutions of k satisfying k^(n-1) == 1 (mod n^2) for a given n. | [
"2",
"3",
"2",
"5",
"2",
"7",
"2",
"3",
"2",
"11",
"2",
"13",
"2",
"5",
"2",
"17",
"2",
"19",
"2",
"5",
"2",
"23",
"2",
"5",
"2",
"3",
"4",
"29",
"2",
"31",
"2",
"5",
"2",
"5",
"2",
"37",
"2",
"5",
"2",
"41",
"2",
"43",
"2",
"9",
"2",
"47",
"2",
"7",
"2",
"5",
"4",
"53",
"2",
"5",
"2",
"5",
"2",
"59",
"2",
"61",
"2",
"5",
"2",
"17",
"6",
"67",
"2",
"5",
"4",
"71",
"2",
"73",
"2",
"5",
"4",
"5",
"2",
"79",
"2",
"3",
"2",
"83",
"2",
"17",
"2",
"5",
"2",
"89"
] | [
"nonn"
] | 36 | 2 | 1 | [
"A056020",
"A056021",
"A056022",
"A056024",
"A056025",
"A056028",
"A056031",
"A056034",
"A056035",
"A063994",
"A381319"
] | null | Mike Sheppard, Feb 20 2025 | 2025-04-10T08:37:24 | oeisdata/seq/A381/A381319.seq | 6da3ab617f27bd0109e225cc498364ce |
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