OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..307
MAPLE
a:= proc(n) option remember; `if`(n=0, 1, add(
a(n-i)*binomial(n-1, i-1)^2*(i-1)!, i=1..n))
end:
seq(a(n), n=0..20); # Alois P. Heinz, Aug 13 2019
MATHEMATICA
nmax=20; b = ConstantArray[0, nmax+2]; b[[1]]=1; Do[b[[n+2]] = Sum[n!/k!*Binomial[n, k]*b[[k+1]], {k, 0, n}], {n, 0, nmax}]; b (* Vaclav Kotesovec, Mar 02 2014 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Sep 04 2005
STATUS
approved