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 A227899 #11 Oct 15 2013 03:10:28
%S A227899 0,0,0,1,1,1,1,2,1,2,2,1,3,2,1,2,2,1,2,3,2,3,3,2,3,2,3,1,1,3,2,4,2,3,
%T A227899 3,3,4,1,2,6,2,4,2,3,5,4,2,3,4,4,4,4,2,1,2,4,2,4,2,6,7,5,3,3,9,2,3,3,
%U A227899 2,4,4,3,1,2,8,3,6,2,2,8,4,7,2,2,5,2,3,3,2,8,3,3,1,4,7,5,9,2,2,5
%N A227899 Number of primes p < n with 3*p - 4 and n^2 + (n - p)^2 both prime.
%C A227899 Conjecture: a(n) > 0 for all n > 3.
%H A227899 Zhi-Wei Sun, <a href="/A227899/b227899.txt">Table of n, a(n) for n = 1..10000</a>
%H A227899 Zhi-Wei Sun, <a href="http://arxiv.org/abs/1211.1588">Conjectures involving primes and quadratic forms</a>, preprint, arXiv:1211.1588.
%e A227899 a(5) = 1 since 5 = 3 + 2, and the three numbers 3, 3*3 - 4 = 5 and 5^2 + (5-3)^2 = 29 are all prime.
%t A227899 a[n_]:=Sum[If[PrimeQ[3Prime[i]-4]&&PrimeQ[n^2+(n-Prime[i])^2],1,0],{i,1,PrimePi[n-1]}]
%t A227899 Table[a[n],{n,1,100}]
%Y A227899 Cf. A069003, A185636, A204065, A227898, A230223.
%K A227899 nonn
%O A227899 1,8
%A A227899 _Zhi-Wei Sun_, Oct 14 2013