OFFSET
0,3
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..400
FORMULA
E.g.f.: 1/( Sum_{n>=0} (-x)^(n^2) / (n^2)! ).
EXAMPLE
E.g.f.: A(x) = 1 + x + 2*x^2/2! + 6*x^3/3! + 23*x^4/4! + 110*x^5/5! + ...
where
1/A(x) = 1 - x + x^4/4! - x^9/9! + x^16/16! - x^25/25! + x^36/36! + ...
PROG
(PARI) {a(n)=n!*polcoeff(sum(m=0, sqrtint(n+1), (-1)^m*x^(m^2)/(m^2)!+x*O(x^n))^(-1), n)}
for(n=0, 25, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 31 2012
STATUS
approved