OFFSET
5,2
COMMENTS
Normalized Delta generates Ramanujan tau function. The 5th power is a weight-60 cusp form.
LINKS
G. C. Greubel, Table of n, a(n) for n = 5..1000
FORMULA
G.f.: q^5 * Prod_{n >= 1} (1-q^n)^120.
EXAMPLE
(normalized Delta)^5 = (tau(1)q+tau(2)q^2+ ... )^5 = q^5-120q^6+ ....
MATHEMATICA
s = q^5 QPochhammer[q]^120 + O[q]^22; Drop[CoefficientList[s, q], 5] (* Jean-François Alcover, Jul 27 2016 *)
PROG
(PARI) q='q+O('q^30); Vec(q^5*eta(q)^120) \\ G. C. Greubel, Apr 27 2018
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Barry Brent (barryb(AT)primenet.com)
STATUS
approved