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 A137271 #2 Mar 30 2012 18:35:47
%S A137271 2,5,14,17,18,43,44,54,107,121,137,144,417,424,868,990,991,1094,2529,
%T A137271 2586,2740,2741,2785,2878,2948,3085,3176,3267,3269,3346,7319,7694,
%U A137271 7750,7868,7984,8061,8161,8250,8308,8340,21182,22190,22801,23200,57448
%N A137271 Numbers n such that pi(n^2)=pi((n-k)^2)+n, where k=A000193(n).
%t A137271 Do[k=Round[Log[n]];If[PrimePi[n^2]==PrimePi[(n-k)^2]+n, Print[n]], {n,1,10^5,1}]
%Y A137271 Cf. A000193, A000720.
%K A137271 nonn
%O A137271 1,1
%A A137271 _Manuel Valdivia_, Mar 13 2007