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.

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A384761 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of e.g.f. B(x)^k, where B(x) is the e.g.f. of A384760.

Original entry on oeis.org

1, 1, 0, 1, -1, 0, 1, -2, 1, 0, 1, -3, 4, 5, 0, 1, -4, 9, 4, -35, 0, 1, -5, 16, -9, -104, -281, 0, 1, -6, 25, -40, -171, -112, 5671, 0, 1, -7, 36, -95, -176, 717, 14164, 42671, 0, 1, -8, 49, -180, -35, 2176, 20619, -18104, -2179127, 0
Offset: 0

Views

Author

Seiichi Manyama, Jun 09 2025

Keywords

Examples

			Square array begins:
  1,    1,    1,    1,    1,    1, ...
  0,   -1,   -2,   -3,   -4,   -5, ...
  0,    1,    4,    9,   16,   25, ...
  0,    5,    4,   -9,  -40,  -95, ...
  0,  -35, -104, -171, -176,  -35, ...
  0, -281, -112,  717, 2176, 3875, ...
		

Crossrefs

Columns k=0..1 give A000007, A384760.
Cf. A379168.

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, (-1)^n*k*sum(j=0, n, (n+k)^(j-1)*binomial(n, j)*a(n-j, j)));

Formula

A(n,0) = 0^n; A(n,k) = (-1)^n * k * Sum_{j=0..n} (n+k)^(j-1) * binomial(n,j) * A(n-j,j).

A384757 E.g.f. A(x) satisfies A(x) = exp( -x * A(-x*A(x)) ).

Original entry on oeis.org

1, -1, -1, 14, 9, -1516, 4345, 507870, -4984063, -367545880, 7749976401, 471799390490, -18036953224367, -948817553760324, 60774529797257081, 2736041193224490494, -284790488755979731455, -10493764378757426300848, 1792499910367109444364961, 49177040508763120698604578
Offset: 0

Views

Author

Seiichi Manyama, Jun 09 2025

Keywords

Examples

			E.g.f.: A(x) = 1 - x - x^2/2 + 14*x^3/6 + 9*x^4/24 - 1516*x^5/120 + ...
A(-x*A(x)) =  1 + x - 3*x^2/2 - 11*x^3/6 + 233*x^4/24 + 621*x^5/120 - ...
		

Crossrefs

Column k=1 of A384758.

Programs

  • PARI
    a(n, k=1) = if(k==0, 0^n, (-1)^n*k*sum(j=0, n, (n-j+k)^(j-1)*binomial(n, j)*a(n-j, j)));

Formula

See A384758.
Showing 1-2 of 2 results.