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Coefficients in q-expansion of E_2*E_4^2*E_6, where E_2, E_4, E_6 are the Eisenstein series shown in A006352, A004009, A013973, respectively.
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%I #13 Feb 27 2018 04:58:04

%S 1,-48,-196128,-33542976,-678319104,12136422240,509314518144,

%T 7469015889792,68272650653760,458377820557584,2454769903187520,

%U 11035857376010304,43103740076823552,149954656815201504,473331019057949952,1375248429330791040,3719662610125117632

%N Coefficients in q-expansion of E_2*E_4^2*E_6, where E_2, E_4, E_6 are the Eisenstein series shown in A006352, A004009, A013973, respectively.

%H Seiichi Manyama, <a href="/A282596/b282596.txt">Table of n, a(n) for n = 0..1000</a>

%t terms = 17;

%t E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];

%t E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];

%t E6[x_] = 1 - 504*Sum[k^5*x^k/(1 - x^k), {k, 1, terms}];

%t E2[x]* E4[x]^2 *E6[x] + O[x]^terms // CoefficientList[#, x]& (* _Jean-François Alcover_, Feb 27 2018 *)

%Y Cf. A282102 (E_2*E_4*E_6), A282547 (E_2*E_4*E_6^2).

%K sign

%O 0,2

%A _Seiichi Manyama_, Feb 19 2017