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 A218213 #7 Oct 23 2012 21:58:40
%S A218213 1,4,13,30,69,187,519,1401,3889,10861,31640,90735
%N A218213 Number of n-digit primes representable as sums of consecutive squares.
%C A218213 There are no common representations of two, three or six squares for n < 13, so
%C A218213 a(n) = A218207(n) + A218209(n) + A218211(n); n < 13.
%F A218213 a(n) = A218214(n) - A218213(n-1).
%t A218213 nn = 8; nMax = 10^nn; t = Table[0, {nn}]; Do[k = n; s = 0; While[s = s + k^2; s <= nMax, If[PrimeQ[s], t[[Ceiling[Log[10, s]]]]++]; k++], {n, Sqrt[nMax]}]; t (* _T. D. Noe_, Oct 23 2012 *)
%Y A218213 Cf. A027861, A027862, A027863, A027864, A027866, A027867, A218207, A218209, A218211.
%K A218213 nonn,base
%O A218213 1,2
%A A218213 _Martin Renner_, Oct 23 2012