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.

A099131 Quintisection and binomial transform of 1/(1-x^4-x^5).

Original entry on oeis.org

1, 1, 1, 1, 2, 7, 22, 57, 128, 264, 529, 1079, 2290, 5022, 11148, 24633, 53824, 116472, 250880, 540536, 1167937, 2531061, 5494247, 11928731, 25880583, 56101768, 121544393, 263289438, 570427339, 1236159756, 2679343966, 5807782301
Offset: 0

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Author

Paul Barry, Sep 29 2004

Keywords

Programs

  • Mathematica
    LinearRecurrence[{5, -10, 10, -4, 1}, {1, 1, 1, 1, 2}, 32] (* Jean-François Alcover, Sep 21 2017 *)

Formula

G.f.: (1-x)^4/((1-x)^5-x^4); a(n)=sum{k=0..floor(5n/4), binomial(k, 5n-4k)}; a(n)=A017827(5n).
a(n)=sum{k=0..floor((n+1)/2), binomial(n+k, 5k)}; - Paul Barry, May 09 2005