OFFSET
5,1
COMMENTS
Also the number of ballot sequences of length n where 5 is the position of the last occurrence of the minimal value.
LINKS
Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 5..100
Wikipedia, Young tableau
MATHEMATICA
b[n_, l_List] := b[n, l] = If[n == 0, 1, Sum[If[i == 1 || l[[i-1]]>l[[i]], b[n-1, ReplacePart[l, i -> l[[i]]+1]], 0], {i, 1, Length[l]}] + Function[{p}, p +(x^(1+Total[l])-1)*Coefficient[p, x, 0]][b[n-1, Append[l, 1]]]]; a[n_] := Coefficient[ b[n, {}], x, 5]; Table[Print["a(", n, ") = ", an = a[n]]; an , {n, 5, 40}] (* Jean-François Alcover, Feb 06 2015, after Maple code in A238794 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jul 09 2014
STATUS
approved