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 A218491 #24 Sep 04 2013 10:28:04
%S A218491 0,0,0,1,0,1,0,1,1,0,2,2,0,2,2,1,1,2,3,2,3,3,2,1,4,1,5,2,3,2,5,2,3,4,
%T A218491 2,5,6,6,5,3,3,5,5,6,4,7,5,9,5,7,4,6,6,5,5,7,4,9,8,4,9,6,10,8,10,7,9,
%U A218491 9,7,9,8,9,13,10,10,11,7,13,7,10,8,11,10,13
%N A218491 Number of ways that prime(n) can be represented as the sum of four nonzero squares.
%C A218491 a(pi(A213721(n))) = n, where pi(n) is the prime counting function.
%H A218491 Arkadiusz Wesolowski, <a href="/A218491/b218491.txt">Table of n, a(n) for n = 1..1000</a>
%H A218491 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>
%e A218491 a(11) = 2 because prime(11) = 31 = 2*1 + 4 + 25 = 4 + 3*9.
%t A218491 Table[Count[PowersRepresentations[Prime[n], 4, 2], _?(Min[#] > 0 &)], {n, 84}]
%Y A218491 Cf. A025428, A213721.
%K A218491 nonn
%O A218491 1,11
%A A218491 _Arkadiusz Wesolowski_, Nov 02 2012