|
%I #27 Feb 18 2023 07:30:00
%S 1,144,193104,16809408,397822032,4630076640,34416785088,187487524224,
%T 814891939920,2975535123408,9486534607200,27053022904128,
%U 70486183583424,169931012132448,384163644219264,820166796086400
%N Duplicate of A008700.
%C Original title: Theta series of Niemeier lattice of type A_5^4*D_4.
%F This series is the q-expansion of 2/3 E_4(z)^3 + 1/3 E_6(z)^2. Cf. A004009, A013973. - _Daniel D. Briggs_, Nov 25 2011
%t terms = 16; E4[q_] := 1 + 240 Sum[DivisorSigma[3, n]*q^(2 n), {n, 1, terms}]; E6[q_] := 1 - 504 Sum[DivisorSigma[5, n]*q^(2 n), {n, 1, terms}]; s = 2/3 E4[q]^3 + 1/3 E6[q]^2 + O[q]^(3 terms); Partition[ CoefficientList[s, q], 2][[All, 1]][[1 ;; terms]] (* _Jean-François Alcover_, Jul 06 2017 *)
%Y Equal to the theta series of D_4^6, A008700.
%K dead
%O 0,2
%A _N. J. A. Sloane_
%E More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jul 05 2000
|
