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Coefficients in expansion of 691*E_6^2*E_12.
3

%I #12 Feb 26 2018 10:18:39

%S 691,-631008,220745952,-97839374976,19569814631136,4535334591238080,

%T 303188772007707264,10484562664742729472,226123357637141848800,

%U 3395301924051385082784,38309171317486687195200,343029821520447762390144,2537867756328299498904192

%N Coefficients in expansion of 691*E_6^2*E_12.

%H Seiichi Manyama, <a href="/A290010/b290010.txt">Table of n, a(n) for n = 0..1000</a>

%t terms = 13;

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

%t E12[x_] = 1 + (65520/691)*Sum[k^11*x^k/(1 - x^k), {k, 1, terms}];

%t 691*E6[x]^2*E12[x] + O[x]^terms // CoefficientList[#, x]& (* _Jean-François Alcover_, Feb 26 2018 *)

%Y Cf. A013973 (E_6), A029828 (691*E_12), A280869 (E_6^2).

%Y Cf. A290009.

%K sign

%O 0,1

%A _Seiichi Manyama_, Jul 17 2017