A282595 Coefficients in q-expansion of E_2^2*E_6, where E_2 and E_6 are respectively the Eisenstein series A006352 and A013973.

1, -552, 7992, 460896, -3450504, -88161264, -728085024, -3775195968, -14894175240, -48567693576, -137214605232, -347495426784, -804758753568, -1733365307184, -3511286411328, -6753825302976, -12422812497672, -21971174382288, -37567247938344

Offset: 0

Author

Seiichi Manyama, Feb 19 2017

Keywords

• sign

Links

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

Crossrefs

Cf. A282018 (E_2^3), this sequence (E_2^2*E_6), A282576 (E_2*E_6^2), A282253 (E_6^3).

Programs

Mathematica

terms = 19;
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}];
E2[x]^2*E6[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 27 2018 *)