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.

A244106 Number of ballot sequences of length n having 9 largest parts.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 4862, 16796, 41990, 90440, 177650, 326876, 572033, 961400, 1562275, 416782080, 2904006105, 20591110410, 93272863125, 429784750200, 1588873361400, 5988317533044, 19637330636352, 65753496366140, 376581209597560, 2635731247693060
Offset: 9

Views

Author

Joerg Arndt and Alois P. Heinz, Jun 20 2014

Keywords

Comments

Also number of standard Young tableaux with last row of length 9.

Crossrefs

Column k=9 of A238123.

Programs

  • Mathematica
    b[n_, l_List] := b[n, l] = If[n < 1, x^l[[-1]], b[n - 1, Append[l, 1]] + Sum[If[i == 1 || l[[i - 1]] > l[[i]], b[n - 1, ReplacePart[l, i -> l[[i]] + 1]], 0], {i, 1, Length[l]}]]; a[n_] := Coefficient[b[n - 1, {1}], x, 9]; Table[a[n], {n, 9, 30}] (* Jean-François Alcover, Feb 10 2015, after A238123 *)