OFFSET
0,3
FORMULA
E.g.f.: Sum(Sum((-1)^(n-k)*binomial(n,k)*(exp((k-1)*x)-1)^k*(exp(k*x)-1)^(n-k),k=0..n),n=0..infinity).
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Sep 03 2006
EXTENSIONS
More terms from Max Alekseyev, Jul 29 2009
STATUS
approved