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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A086631 Antidiagonal sums of square table A086629.

Original entry on oeis.org

1, 2, 4, 10, 29, 92, 310, 1088, 3931, 14518, 54551, 207856, 801202, 3118532, 12239732, 48385852, 192483953, 769974110, 3095236066, 12497442266, 50660112478, 206093561590, 841151382755, 3443278744832, 14133534466258
Offset: 0

Views

Author

Paul D. Hanna, Jul 24 2003

Keywords

Crossrefs

Cf. A001764, A086615, A086629 (table), A086630 (diagonal).

Programs

  • PARI
    a(n) = sum(k=0, n\2, binomial(n+2*k+1, 4*k+1)*binomial(3*k, k)/(2*k+1)); \\ Seiichi Manyama, Jul 30 2023

Formula

G.f.: A(x) = 1/(1-x)^2 + x^2*A(x)^3.
a(n) = Sum_{k=0..floor(n/2)} binomial(n+2*k+1,4*k+1) * binomial(3*k,k) / (2*k+1). - Seiichi Manyama, Jul 30 2023

A086630 Main diagonal of square table A086629; coefficients of x^n*y^n in f(x,y) that satisfies f(x,y) = 1/[(1-x)(1-y)] + xy*f(x,y)^3.

Original entry on oeis.org

1, 2, 13, 124, 1419, 18037, 245650, 3513260, 52114339, 795230788, 12411836882, 197327486617, 3185686181794, 52101500060794, 861628197679360
Offset: 0

Views

Author

Paul D. Hanna, Jul 24 2003

Keywords

Crossrefs

Cf. A086629 (table), A086631 (antidiagonal sums).
Showing 1-2 of 2 results.