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 A055403 #11 Sep 29 2019 13:19:56 %S A055403 1,5,20,70,165,357,688,1154,1867,2907,4272,6070,8357,11307,14998, %T A055403 19470,24809,31211,38928,47816,58201,70361,83962,99648,117519,137521, %U A055403 160270,185528,213615,244649,279370,317006,358809,404823,454838,509486,568493 %N A055403 Number of points in N^4 of norm <= n. %H A055403 Andrew Howroyd, <a href="/A055403/b055403.txt">Table of n, a(n) for n = 0..500</a> %F A055403 a(n) = [x^(n^2)] (1 + theta_3(x))^4/(16*(1 - x)), where theta_3() is the Jacobi theta function. - _Ilya Gutkovskiy_, Apr 15 2018 %Y A055403 Column k=4 of A302998. %K A055403 nonn %O A055403 0,2 %A A055403 _David W. Wilson_