OFFSET
0,4
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..200
EXAMPLE
G.f.: A(x) = 1 + x + x^2 + 2*x^3 + 7*x^4 + 31*x^5 + 158*x^6 + 907*x^7 +...
where
A(x) = 1 + x*(1-x)/(1-x) + x^2*(1-x)*(1-2*x)/((1-x)*(1-3*x)) + x^3*(1-x)*(1-2*x)*(1-3*x)/((1-x)*(1-3*x)*(1-5*x)) +...
PROG
(PARI) {a(n)=polcoeff(sum(m=0, n, x^m*prod(k=1, m, (1-k*x)/(1-(2*k-1)*x +x*O(x^n)))), n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 22 2011
STATUS
approved