A185653 Expansion of exp( Sum_{n>=1} -3*sigma(2n)*x^n/n ) in powers of x.
1, -9, 30, -39, 0, 18, 49, 0, -192, 110, 81, 78, -130, 0, -30, -121, 0, 210, 320, -270, 0, -407, 0, 192, 190, 0, 0, 0, 351, -210, -418, 0, -510, 448, 0, 462, 611, 0, -960, 50, 0, 0, -350, 0, 450, -361, -162, 960, 0, 0, 798, -782, 0, -1170, -290, -441, 702, 850, 0, 0, 576
Offset: 0
Keywords
Examples
G.f. = 1 - 9*x + 30*x^2 - 39*x^3 + 18*x^5 + 49*x^6 - 192*x^8 + 110*x^9 + ...
Links
- Paul D. Hanna, Table of n, a(n) for n = 0..1024
Programs
-
PARI
{a(n)=polcoeff(exp(sum(m=1,n,-3*sigma(2*m)*x^m/m)+x*O(x^n)),n)} -
PARI
{a(n)=local(X=x+x*O(x^n));polcoeff(eta(X)^9/eta(X^2)^3,n)}
Comments