A282752 Coefficients in q-expansion of E_2^2*E_4^2, where E_2 and E_4 are respectively the Eisenstein series A006352 and A004009.

1, 432, 39312, -1711296, -14159664, 317412000, 5783500224, 47251354752, 263098098000, 1138294453104, 4105673192160, 12882680040384, 36171259008192, 92764213434144, 220523509245312, 491705284878720, 1037366470830672, 2086141009345632, 4022101701933264

Offset: 0

Author

Seiichi Manyama, Feb 21 2017

Keywords

• sign

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A282019 (E_2*E_4), A282208 (E_2^2*E_4), A282101 (E_2*E_4^2).

Programs

Mathematica

terms = 19;
E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
E2[x]^2*E4[x]^2 + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 27 2018 *)