OFFSET
0,5
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..210
EXAMPLE
G.f.: A(x) = 1 + x + x^2 + x^3 + 2*x^4 + 3*x^5 + 7*x^6 + 15*x^7 + 38*x^8 +...
where
A(x) = 1 + x*(1+x)/(1 + x*(1+x)) + x^2*(1+x)^3/((1+x*(1+x))*(1+x*(1+x)^2)) + x^3*(1+x)^6/((1+x*(1+x))*(1+x*(1+x)^2)*(1+x*(1+x)^3)) + x^4*(1+x)^10/((1+x*(1+x))*(1+x*(1+x)^2)*(1+x*(1+x)^3)*(1+x*(1+x)^4)) +...
PROG
(PARI) {a(n)=polcoeff(sum(m=0, n, x^m*(1+x)^(m*(m+1)/2)/prod(k=1, m, (1+x*(1+x)^k+x*O(x^n)))), n)}
for(n=0, 30, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 19 2013
STATUS
approved