OFFSET
0,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..250
FORMULA
a(n) ~ c * (n!)^2, where c = 0.80799863989712622039... - Vaclav Kotesovec, Feb 22 2014
PROG
(PARI) {a(n)=local(A=1+x); for(i=0, n, A=exp(x+x^2*deriv(A)+x*O(x^n))); n!*polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Sep 06 2008
STATUS
approved