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 A078183 #4 Mar 30 2012 17:22:26
%S A078183 0,1,27,93,251,485,895,1365,2103,2969,4139,5497,7123,9093,11459,13997,
%T A078183 17071,20377,24303,28545,33371,38641,44395,50733,57747,65117,73447,
%U A078183 82201,91911,101769,112931,124289,137059,150165,164415,179309,195167
%N A078183 Number of solutions to x^2 + y^2 + z^2 < n^2; number of lattice points inside a sphere of radius n.
%F A078183 a(n) = A000605(n) - A016725(n)
%t A078183 s = 0; Table[s = s + Sum[SquaresR[3, k], {k, (n - 1)^2, n^2 - 1}], {n, 0, 50}]
%Y A078183 Cf. A000605, A016725.
%K A078183 nonn
%O A078183 0,3
%A A078183 _T. D. Noe_, Nov 21 2002