OFFSET
1,4
COMMENTS
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..420
FORMULA
a(n) ~ n! * n^2 / (24 * (log(2))^n). - Vaclav Kotesovec, May 03 2015
MAPLE
b:= proc(n, t) option remember; `if`(n=0, [1, 0], add((p-> p+
[0, p[1]*j*(j-1)*t/6])(b(n-j, t+j))*binomial(n, j), j=1..n))
end:
a:= n-> b(n, 0)[2]:
seq(a(n), n=1..25); # Alois P. Heinz, Dec 08 2014
MATHEMATICA
b[n_, t_] := b[n, t] = If[n==0, {1, 0}, Sum[Function[p, p+{0, p[[1]]*j*(j-1)*t/6}][b[n-j, t+j]]*Binomial[n, j], {j, 1, n}]]; a[n_] := b[n, 0][[2]]; Table[a[n], {n, 1, 25}] (* Jean-François Alcover, Feb 28 2017, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 13 2014
EXTENSIONS
a(8)-a(20) from Alois P. Heinz, Dec 08 2014
STATUS
approved