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 A237819 #7 Feb 13 2014 14:39:09
%S A237819 0,0,0,0,0,1,2,2,3,3,4,4,4,4,5,5,6,5,4,4,4,4,4,4,4,4,5,6,5,6,6,7,7,7,
%T A237819 7,8,8,8,6,6,6,7,6,7,7,7,6,7,6,6,7,7,5,6,5,6,6,6,4,4,4,5,5,5,5,6,5,6,
%U A237819 5,5,6,7,6,6,6,6,5,6,5,5
%N A237819 Number of primes p < n such that floor(sqrt(n-p)) is a Sophie Germain prime.
%C A237819 Conjecture: (i) a(n) > 0 for all n > 5.
%C A237819 (ii) For any integer n > 10, there is a prime p < n such that q = floor(sqrt(n-p)) and q + 2 are both prime.
%H A237819 Zhi-Wei Sun, <a href="/A237819/b237819.txt">Table of n, a(n) for n = 1..10000</a>
%e A237819 a(6) = 1 since 2, floor(sqrt(6-2)) = 2 and 2*2 + 1 = 5 are all prime.
%t A237819 f[n_]:=Floor[Sqrt[n]]
%t A237819 q[n_]:=PrimeQ[f[n]]&&PrimeQ[2*f[n]+1]
%t A237819 a[n_]:=Sum[If[q[n-Prime[k]],1,0],{k,1,PrimePi[n-1]}]
%t A237819 Table[a[n],{n,1,80}]
%Y A237819 Cf. A000040, A001359, A005384, A006512, A237720, A237721, A237815, A237817.
%K A237819 nonn
%O A237819 1,7
%A A237819 _Zhi-Wei Sun_, Feb 13 2014