cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-6 of 6 results.

A384581 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A143501.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 3, 3, 4, 0, 1, 4, 6, 10, 16, 0, 1, 5, 10, 19, 41, 92, 0, 1, 6, 15, 32, 78, 224, 616, 0, 1, 7, 21, 50, 131, 411, 1464, 4729, 0, 1, 8, 28, 74, 205, 672, 2617, 11002, 40776, 0, 1, 9, 36, 105, 306, 1031, 4170, 19251, 93234, 388057, 0
Offset: 0

Views

Author

Seiichi Manyama, Jun 04 2025

Keywords

Examples

			Square array begins:
  1,   1,    1,    1,    1,    1,    1, ...
  0,   1,    2,    3,    4,    5,    6, ...
  0,   1,    3,    6,   10,   15,   21, ...
  0,   4,   10,   19,   32,   50,   74, ...
  0,  16,   41,   78,  131,  205,  306, ...
  0,  92,  224,  411,  672, 1031, 1518, ...
  0, 616, 1464, 2617, 4170, 6245, 8997, ...
		

Crossrefs

Columns k=0..1 give A000007, A143501.

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(3*n-3*j+k, j)/(3*n-3*j+k)*a(n-j, j)));

Formula

A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} binomial(3*n-3*j+k,j)/(3*n-3*j+k) * A(n-j,j).

A384582 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A384574.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 3, 3, 5, 0, 1, 4, 6, 12, 23, 0, 1, 5, 10, 22, 57, 155, 0, 1, 6, 15, 36, 105, 366, 1236, 0, 1, 7, 21, 55, 171, 651, 2853, 11286, 0, 1, 8, 28, 80, 260, 1032, 4951, 25584, 116333, 0, 1, 9, 36, 112, 378, 1536, 7656, 43587, 259789, 1329433, 0
Offset: 0

Views

Author

Seiichi Manyama, Jun 04 2025

Keywords

Examples

			Square array begins:
  1,    1,    1,    1,    1,     1,     1, ...
  0,    1,    2,    3,    4,     5,     6, ...
  0,    1,    3,    6,   10,    15,    21, ...
  0,    5,   12,   22,   36,    55,    80, ...
  0,   23,   57,  105,  171,   260,   378, ...
  0,  155,  366,  651, 1032,  1536,  2196, ...
  0, 1236, 2853, 4951, 7656, 11125, 15552, ...
		

Crossrefs

Columns k=0..1 give A000007, A384574.

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(4*n-4*j+k, j)/(4*n-4*j+k)*a(n-j, j)));

Formula

A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} binomial(4*n-4*j+k,j)/(4*n-4*j+k) * A(n-j,j).

A384583 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A384575.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 3, 3, 6, 0, 1, 4, 6, 14, 31, 0, 1, 5, 10, 25, 75, 236, 0, 1, 6, 15, 40, 135, 546, 2166, 0, 1, 7, 21, 60, 215, 951, 4902, 22722, 0, 1, 8, 28, 86, 320, 1476, 8338, 50620, 269889, 0, 1, 9, 36, 119, 456, 2151, 12634, 84714, 593347, 3567412, 0
Offset: 0

Views

Author

Seiichi Manyama, Jun 04 2025

Keywords

Examples

			Square array begins:
  1,    1,    1,    1,     1,     1,     1, ...
  0,    1,    2,    3,     4,     5,     6, ...
  0,    1,    3,    6,    10,    15,    21, ...
  0,    6,   14,   25,    40,    60,    86, ...
  0,   31,   75,  135,   215,   320,   456, ...
  0,  236,  546,  951,  1476,  2151,  3012, ...
  0, 2166, 4902, 8338, 12634, 17985, 24627, ...
		

Crossrefs

Columns k=0..1 give A000007, A384575.

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(5*n-5*j+k, j)/(5*n-5*j+k)*a(n-j, j)));

Formula

A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} binomial(5*n-5*j+k,j)/(5*n-5*j+k) * A(n-j,j).

A384580 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A143500.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 3, 3, 3, 0, 1, 4, 6, 8, 10, 0, 1, 5, 10, 16, 27, 46, 0, 1, 6, 15, 28, 54, 118, 244, 0, 1, 7, 21, 45, 95, 228, 609, 1481, 0, 1, 8, 28, 68, 155, 392, 1144, 3602, 10020, 0, 1, 9, 36, 98, 240, 631, 1916, 6597, 23866, 74400, 0
Offset: 0

Views

Author

Seiichi Manyama, Jun 04 2025

Keywords

Examples

			Square array begins:
  1,   1,   1,    1,    1,    1,    1, ...
  0,   1,   2,    3,    4,    5,    6, ...
  0,   1,   3,    6,   10,   15,   21, ...
  0,   3,   8,   16,   28,   45,   68, ...
  0,  10,  27,   54,   95,  155,  240, ...
  0,  46, 118,  228,  392,  631,  972, ...
  0, 244, 609, 1144, 1916, 3015, 4560, ...
		

Crossrefs

Columns k=0..2 give A000007, A143500, A384576.

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n-2*j+k, j)/(2*n-2*j+k)*a(n-j, j)));

Formula

A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} binomial(2*n-2*j+k,j)/(2*n-2*j+k) * A(n-j,j).

A381567 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A381568.

Original entry on oeis.org

1, 1, 0, 1, 2, 0, 1, 4, 5, 0, 1, 6, 14, 22, 0, 1, 8, 27, 64, 126, 0, 1, 10, 44, 134, 365, 884, 0, 1, 12, 65, 240, 777, 2492, 7149, 0, 1, 14, 90, 390, 1438, 5238, 19578, 64688, 0, 1, 16, 119, 592, 2440, 9696, 40244, 172356, 641836, 0, 1, 18, 152, 854, 3891, 16632, 73408, 345726, 1668686, 6888740, 0
Offset: 0

Views

Author

Seiichi Manyama, Feb 28 2025

Keywords

Examples

			Square array begins:
  1,    1,     1,     1,     1,      1,      1, ...
  0,    2,     4,     6,     8,     10,     12, ...
  0,    5,    14,    27,    44,     65,     90, ...
  0,   22,    64,   134,   240,    390,    592, ...
  0,  126,   365,   777,  1438,   2440,   3891, ...
  0,  884,  2492,  5238,  9696,  16632,  27036, ...
  0, 7149, 19578, 40244, 73408, 125035, 203258, ...
		

Crossrefs

Columns k=0..1 give A000007, A381568.

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n-2*j+2*k, j)/(n-j+k)*a(n-j, j)));

Formula

A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} binomial(2*n-2*j+2*k,j)/(n-j+k) * A(n-j,j).

A381569 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A381570.

Original entry on oeis.org

1, 1, 0, 1, 3, 0, 1, 6, 12, 0, 1, 9, 33, 82, 0, 1, 12, 63, 236, 732, 0, 1, 15, 102, 489, 2100, 7944, 0, 1, 18, 150, 868, 4428, 22248, 99156, 0, 1, 21, 207, 1400, 8121, 46422, 270268, 1381464, 0, 1, 24, 273, 2112, 13665, 85272, 552540, 3668568, 21065853, 0
Offset: 0

Views

Author

Seiichi Manyama, Feb 28 2025

Keywords

Examples

			Square array begins:
  1,    1,     1,     1,     1,      1, ...
  0,    3,     6,     9,    12,     15, ...
  0,   12,    33,    63,   102,    150, ...
  0,   82,   236,   489,   868,   1400, ...
  0,  732,  2100,  4428,  8121,  13665, ...
  0, 7944, 22248, 46422, 85272, 145143, ...
		

Crossrefs

Columns k=0..1 give A000007, A381570.

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(3*n-3*j+3*k, j)/(n-j+k)*a(n-j, j)));

Formula

A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} binomial(3*n-3*j+3*k,j)/(n-j+k) * A(n-j,j).
Showing 1-6 of 6 results.