OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
MATHEMATICA
(* b = A003319 *) b[0] = 0; b[n_] := b[n] = n! - Sum[k!*b[n-k], {k, 1, n-1} ]; a[n_] := b[2n + 1]; Table[a[n], {n, 0, 15}] (* Jean-François Alcover, Feb 18 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 15 2016
STATUS
approved