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 A120884 #4 May 30 2013 13:14:26
%S A120884 1,4,17,35,69,114,184,272,389,528,702,901,1166,1442,1791,2157,2584,
%T A120884 3058,3596,4194,4878,5590,6388,7232,8219,9228,10339,11512,12776,14138,
%U A120884 15600,17172,18865,20621,22493,24420,26559,28768,31109,33512,36117,38781
%N A120884 (1/8)*number of lattice points with odd indices in a cubic lattice inside a sphere around the origin with radius 2*n.
%C A120884 lim n->infinity a(n)/n^3 = Pi/6.
%e A120884 a(2)=4 because the 4 lattice points in the first octant (x,y,z)={(1,1,1), (1,1,3), (1,3,1), (3,1,1)} all satisfy x^2+y^2+z^2 < (2*2)^2.
%Y A120884 Cf. A000605, A117609.
%K A120884 nonn
%O A120884 1,2
%A A120884 _Hugo Pfoertner_, Jul 12 2006