OFFSET
0,2
COMMENTS
EXAMPLE
G.f.: A(x) = 1 + 2*x + 19*x^2 + 964*x^3 + 334965*x^4 + 742714950*x^5 +...
log(A(x)) = 2*x + 34*x^2/2 + 2786*x^3/3 + 1331714*x^4/4 + 3710155682*x^5/5 + 60245508192802*x^6/6 + 5701755387019728962*x^7/7 +...+ A002203(n^2)*x^n/n +...
PROG
(PARI) {a(n)=if(n==0, 1, polcoeff(exp(sum(m=1, n, polcoeff(2*(1-x)/(1-2*x-x^2+x*O(x^(m^2))), m^2)*x^m/m)+x*O(x^(n^2))), n))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 18 2009
STATUS
approved