OFFSET
0,3
FORMULA
EXAMPLE
E.g.f.: A(x) = 1 + x + 4*x^2/2! + 27*x^3/3! + 284*x^4/4! +...
x + x^2*A(x) = x + 2*x^2/2! + 6*x^3/3! + 48*x^4/4! + 540*x^5/5! +...
PROG
(PARI) {a(n)=local(A=[1, 1]); for(i=2, n, A=concat(A, 0); G=x*Ser(A); A[ #A]=polcoeff(1+subst(G, x, G)+O(x^#A)-(1+G)*deriv(G)*x^2/G^2, #A-1)/(#A-2)); if(n<0, 0, n!*A[n+1])}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 23 2010
STATUS
approved