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 A185711 #19 Jul 11 2017 04:51:47
%S A185711 0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,
%T A185711 2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,
%U A185711 4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6
%N A185711 a(n) = number of primes <= n that end in 1.
%C A185711 Partial sums of A185705.
%H A185711 G. C. Greubel, <a href="/A185711/b185711.txt">Table of n, a(n) for n = 1..5000</a>
%H A185711 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 A185711 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 A185711 Accumulate[Table[If[PrimeQ[n]&&Mod[n,10]==1,1,0],{n,120}]] (* _Harvey P. Dale_, May 30 2016 *)
%Y A185711 Cf. A185705, A185706, A185708, A185709, A185711, A185712, A185714, A185715.
%K A185711 base,nonn
%O A185711 1,31
%A A185711 _N. J. A. Sloane_, Feb 10 2011