OFFSET
0,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..250
EXAMPLE
G.f.: A(x) = 1 + x + 3*x^2 + 11*x^3 + 49*x^4 + 273*x^5 + 1859*x^6 +...
where
A(x) = 1 + x*(1-x)/(1-3*x) + x^2*(1-x)*(1-5*x)/((1-3*x)*(1-7*x)) + x^3*(1-x)*(1-5*x)*(1-9*x)/((1-3*x)*(1-7*x)*(1-11*x)) +...
PROG
(PARI) {a(n)=polcoeff(sum(m=0, n, x^m*prod(k=1, m, (1-(4*k-3)*x)/(1-(4*k-1)*x +x*O(x^n)))), n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 22 2011
STATUS
approved