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 A033720 #19 Sep 23 2019 09:06:08 %S A033720 1,2,2,4,4,4,8,8,8,10,12,12,16,20,16,24,24,20,26,20,24,32,24,24,32,30, %T A033720 28,40,32,20,48,32,24,48,36,48,52,36,40,56,48,52,64,44,48,84,48,48,96, %U A033720 50,62,72,56,68,80,72,64 %N A033720 Product theta3(q^d); d | 8. %C A033720 Also number of integer solutions to a^2 +2*b^2 + 4*c^2 + 8*d^2 = n. %D A033720 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p 102 eq 9. %H A033720 Seiichi Manyama, <a href="/A033720/b033720.txt">Table of n, a(n) for n = 0..10000</a> %H A033720 J. Liouville, <a href="http://sites.mathdoc.fr/JMPA/afficher_notice.php?id=JMPA_1861_2_6_A46_0">Sur la forme x^2 + 2y^2 + 4z^2 + 8t^2</a>, Journal de mathématiques pures et appliquées 2e série, tome 6 (1861), p. 409-416. %F A033720 Liouville gives an explicit formula for a(n). %K A033720 nonn %O A033720 0,2 %A A033720 _N. J. A. Sloane_