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 A113898 #6 Jul 22 2021 07:52:11
%S A113898 1196,11373,22517,33597,44639,55646,60062,61159,62256,63346,63347,
%T A113898 64448,64544,64555,64577,64588,64599,64611,64655,64668,64700,64711,
%U A113898 64722,64774,64884,64992,65545,65770,65880,65881,65990,66644,67746,68841
%N A113898 Numbers k such that the value pi(k), the number of primes <= k, can be obtained deleting some of the repeating adjacent digits of k.
%C A113898 Largest value below 10^7 is given by pi(110486) = 10486.
%e A113898 pi(64668) = 6468, pi(99551) = 9551.
%t A113898 lst = {}; p=0; While[p < 10^7, n=PrimePi[ ++p]; {sp, sn}=Split/@IntegerDigits@{p, n}; If[First/@sp==First/@sn && And@@GreaterEqual@@@Transpose[Length/@#&/@{sp, sn}], AppendTo[lst, p]]]; lst
%Y A113898 Cf. A000720, A114924, A080794.
%K A113898 base,nonn
%O A113898 1,1
%A A113898 _Giovanni Resta_, Jan 29 2006