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.

A230957 Boustrophedon transform of partition numbers A000009.

Original entry on oeis.org

1, 2, 4, 10, 29, 94, 364, 1621, 8255, 47277, 300962, 2107479, 16099922, 133243363, 1187555333, 11340314638, 115511502857, 1250127378307, 14325404633040, 173276880401035, 2206229765086251, 29495119298584886, 413097874985119467, 6048684327982905454
Offset: 0

Views

Author

Reinhard Zumkeller, Nov 03 2013

Keywords

Crossrefs

Cf. A000751.

Programs

  • Haskell
    a230957 n = sum $ zipWith (*) (a109449_row n) a000009_list
  • Mathematica
    T[n_, k_] := (n!/k!) SeriesCoefficient[(1 + Sin[x])/Cos[x], {x, 0, n - k}];
    a[n_] := Sum[T[n, k] PartitionsQ[k], {k, 0, n}];
    Table[a[n], {n, 0, 23}] (* Jean-François Alcover, Jul 23 2019 *)

Formula

a(n) = sum(A109449(n,k)*A000009(k): k=0..n).