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.

A085351 Expansion of (1-3*x)/((1-4*x)*(1-5*x)).

Original entry on oeis.org

1, 6, 34, 186, 994, 5226, 27154, 139866, 715714, 3644106, 18482674, 93461946, 471504034, 2374297386, 11938595794, 59961414426, 300880813954, 1508699037066, 7560675054514, 37872094749306, 189635351653474
Offset: 0

Views

Author

Paul Barry, Jun 24 2003

Keywords

Comments

Binomial transform of A085350. Second binomial transform of poly-Bernoulli numbers A027649.

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(1-3x)/((1-4x)(1-5x)),{x,0,20}],x] (* or *) LinearRecurrence[{9,-20},{1,6},30] (* Harvey P. Dale, Jan 07 2022 *)
  • PARI
    Vec((1 - 3*x) / ((1 - 4*x)*(1 - 5*x)) + O(x^25)) \\ Colin Barker, Jun 25 2020

Formula

G.f.: (1-3*x)/((1-4*x)*(1-5*x)).
a(n) = 2*5^n - 4^n.
a(n) = 9*a(n-1) - 20*a(n-2) for n>1. - Colin Barker, Jun 25 2020