OFFSET
-1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = -1..425
Wikipedia, Ramanujan-Sato series.
FORMULA
G.f.: 432 * (1 + (1 - 1728/j)^(1/2)) / (1 - (1 - 1728/j)^(1/2)).
G.f.: 432 * (E_4^(3/2) + E_6) / (E_4^(3/2) - E_6).
a(n) ~ -(-1)^n * 81 * Gamma(1/3)^9 * exp(Pi*sqrt(3)*n) / (2^(3/2) * Pi^(13/2) * n^(5/2)). - Vaclav Kotesovec, Apr 09 2018
EXAMPLE
G.f.: 1/q - 120 + 10260*q - 901120*q^2 + 91676610*q^3 - 10868097024*q^4 + ...
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Feb 22 2018
STATUS
approved