OFFSET
0,3
EXAMPLE
a(n) appears to be divisible by n for n>0:
a(n)/n = [1,1,2,7,49,350,3786,46452,729456,12501720,262551240,...].
PROG
(PARI) {a(n)=local(W=1+x, V, H); for(i=0, n, W=exp(subst(x*W, x, q*x+x*O(x^n)))); V=Vec(Vec(W)[n+1]*n!+O(q^(n*(n+1)/2+1))); H=0; for(k=1, #V, if(V[k]>H, H=V[k])); H}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Dec 25 2006
STATUS
approved