OFFSET
4,2
COMMENTS
Normalized Delta generates Ramanujan tau function. The 4th power is a weight-48 cusp form.
LINKS
G. C. Greubel, Table of n, a(n) for n = 4..1000
FORMULA
G.f.: q^4 * Product_{n >= 1} (1 - q^n)^96.
EXAMPLE
(normalized Delta)^4 = (tau(1)q+tau(2)q^2+ ... )^4 = q^4-96q^5+4464q^6- ....
MATHEMATICA
s = q^4 QPochhammer[q]^96 + O[q]^22; Drop[CoefficientList[s, q], 4] (* Jean-François Alcover, Jul 27 2016 *)
PROG
(PARI) q='q+O('q^30); Vec(q^4*eta(q)^96) \\ G. C. Greubel, Apr 25 2018
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Barry Brent (barryb(AT)primenet.com)
STATUS
approved