This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A008699 #17 Mar 04 2020 18:11:08
%S A008699 1,168,192528,16815456,397786704,4630192560,34416639936,187487122368,
%T A008699 814893967440,2975532395976,9486531825120,27053035734816,
%U A008699 70486174680768,169930998266736,384163653863808
%N A008699 Theta series of Niemeier lattice of type A_6^4.
%D A008699 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 407.
%H A008699 G. C. Greubel, <a href="/A008699/b008699.txt">Table of n, a(n) for n = 0..1000</a>
%F A008699 This series is the q-expansion of (49*E_4(z)^3 + 23*E_6(z)^2)/72. - _Daniel D. Briggs_, Nov 25 2011
%t A008699 terms = 15; 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 = 49/72 E4[q]^3 + 23/72 E6[q]^2 + O[q]^(3 terms); Partition[ CoefficientList[s, q], 2][[All, 1]][[1 ;; terms]] (* _Jean-François Alcover_, Jul 06 2017 *)
%Y A008699 Cf. A004009, A013973.
%Y A008699 Cf. A008688 - A008698, A008700 - A008704.
%K A008699 nonn
%O A008699 0,2
%A A008699 _N. J. A. Sloane_