OFFSET
0,2
MATHEMATICA
terms = 20;
E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
E6[x_] = 1 - 504*Sum[k^5*x^k/(1 - x^k), {k, 1, terms}];
CoefficientList[Series[E2[x]^2*E6[x]^2, {x, 0, 20}], x]
CROSSREFS
KEYWORD
sign
AUTHOR
Vaclav Kotesovec, Aug 03 2025
STATUS
approved