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.

A241635 Number of compositions of n with exactly ten descents.

Original entry on oeis.org

89, 1529, 15072, 109700, 651755, 3333143, 15159290, 62673818, 239267852, 853417204, 2869778022, 9163554647, 27947044811, 81799126374, 230699706092, 629085587197, 1663426352840, 4275866388599, 10708451601656, 26178837135330, 62580214195713, 146503017803381
Offset: 30

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 26 2014

Keywords

Crossrefs

Column k=10 of A238343 and of A238344.

Programs

  • Maple
    b:= proc(n, i) option remember;
          `if`(n=0, 1, convert(series(add(b(n-j, j)*
          `if`(j coeff(b(n, 0), x, 10):
    seq(a(n), n=30..55);
  • Mathematica
    b[n_, i_] := b[n, i] = If[n == 0, 1, Sum[b[n - j, j]*
       If[j < i, x, 1], {j, 1, n}] // Expand];
    a[n_] := Coefficient[b[n, 0], x, 10];
    Table[a[n], {n, 30, 55}] (* Jean-François Alcover, Nov 28 2023, from Maple code *)