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.

A099928 Row sums of Pellonomial triangle A099927.

Original entry on oeis.org

1, 2, 4, 12, 56, 408, 4608, 80784, 2201536, 93224736, 6134017792, 627029574336, 99602689462784, 24580813373119872, 9426621978735869952, 5616371724370667073792, 5199854362208758062125056, 7479400854548558531507839488, 16717751433807850998823619411968
Offset: 0

Views

Author

Ralf Stephan, Nov 03 2004

Keywords

Programs

  • Maple
    p:= proc(n) p(n):= `if`(n<2, n, 2*p(n-1)+p(n-2)) end:
    f:= proc(n) f(n):= `if`(n=0, 1, p(n)*f(n-1)) end:
    a:= n-> add(f(n)/(f(k)*f(n-k)), k=0..n):
    seq(a(n), n=0..20);  # Alois P. Heinz, Aug 15 2013
  • Mathematica
    p[n_] := p[n] = If[n < 2, n, 2*p[n - 1] + p[n - 2]];
    f[n_] := f[n] = If[n == 0, 1, p[n]*f[n - 1]];
    T[n_, k_] := f[n]/(f[k]*f[n - k]);
    a[n_] := Sum[T[n, k], {k, 0, n}];
    Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Nov 16 2022, after Alois P. Heinz *)