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.

A382677 a(n) = 9 - 28 * 2^n + 20 * 3^n.

Original entry on oeis.org

1, 13, 77, 325, 1181, 3973, 12797, 40165, 124061, 379333, 1152317, 3485605, 10514141, 31657093, 95200637, 286060645, 859099421, 2579133253, 7741069757, 23230549285, 69706327901, 209148343813, 627503751677, 1882628695525, 5648120967581, 16944832664773
Offset: 0

Views

Author

Seiichi Manyama, Apr 03 2025

Keywords

Crossrefs

Column k=2 of A382674.
Row n=2 of A382674.

Programs

  • PARI
    a(n) = 9-28*2^n+20*3^n;

Formula

From Stefano Spezia, Aug 30 2025: (Start)
G.f.: (1 + 2*x)*(1 + 5*x)/((1 - x)*(1 - 2*x)*(1 - 3*x)).
E.g.f.: exp(x)*(2*exp(x) - 1)*(10*exp(x) - 9). (End)