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 A005877 M3322 #20 Dec 01 2017 03:03:37 %S A005877 4,8,8,16,12,8,24,16,16,24,16,16,28,32,8,32,32,16,40,16,16,40,40,32, %T A005877 36,16,24,48,32,24,40,48,16,56,32,16,64,40,32,32,36,40,48,48,32,48,48, %U A005877 16,80,40,24,80 %N A005877 Theta series of cubic lattice with respect to square. %D A005877 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 107. %D A005877 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005877 G. C. Greubel, <a href="/A005877/b005877.txt">Table of n, a(n) for n = 0..1000</a> %H A005877 G. Nebe and N. J. A. Sloane, <a href="http://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/cubicP.html">Home page for this lattice</a> %F A005877 a(n) = 4*A045828(n). %t A005877 terms = 52; QP = QPochhammer; s = 4*(QP[q^2]^3*QP[q^4]^2)/QP[q]^2 + O[q]^terms; CoefficientList[s, q] (* _Jean-François Alcover_, Jul 05 2017 *) %Y A005877 Cf. A045828. %K A005877 nonn,easy %O A005877 0,1 %A A005877 _N. J. A. Sloane_