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 A185714 #17 Jul 11 2017 04:52:01
%S A185714 0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
%T A185714 2,2,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,
%U A185714 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7
%N A185714 a(n) = number of primes <= n that end in 7.
%C A185714 Partial sums of A185708.
%H A185714 G. C. Greubel, <a href="/A185714/b185714.txt">Table of n, a(n) for n = 1..5000</a>
%H A185714 A. Granville and G. Martin, <a href="http://www.arXiv.org/abs/math.NT/0408319">Prime number races</a>, arXiv:math/0408319 [math.NT], 2004.
%H A185714 A. Granville and G. Martin, <a href="http://www.dms.umontreal.ca/~andrew/PDF/PrimeRace.pdf">Prime number races</a>, Amer. Math. Monthly, 113 (No. 1, 2006), 1-33.
%t A185714 Accumulate[Table[If[PrimeQ[n] && Mod[n, 10] == 7, 1, 0], {n, 50}]] (* _G. C. Greubel_, Jul 10 2017 *)
%Y A185714 Cf. A185705, A185706, A185708, A185709, A185711, A185712, A185714, A185715.
%K A185714 base,nonn
%O A185714 1,17
%A A185714 _N. J. A. Sloane_, Feb 10 2011