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 A231788 #8 May 21 2014 17:11:28
%S A231788 3,23,303,3503,44448,487900,5289359,57794031,658775109,7212208422,
%T A231788 77028673251
%N A231788 Count of the first 10^n primes containing at least one 2's digit.
%F A231788 a(n) ~ 10^n. - _Charles R Greathouse IV_, May 21 2014
%e A231788 a(1)=3 because there are 3 primes not greater than 29 (the 10th prime) that contain a 2's digit. Namely: 2, 23, 29.
%t A231788 cnt = 0; Table[Do[p = Prime[k]; If[MemberQ[IntegerDigits[p], 2], cnt++], {k, 10^(n - 1) + 1, 10^n}]; cnt, {n, 5}] (* _T. D. Noe_, Nov 13 2013 *)
%Y A231788 Cf. A231726-A231790, A231792-A231796, A091634-A091643, A231412, A228413-A228421.
%K A231788 more,nonn,base
%O A231788 1,1
%A A231788 _Robert Price_, Nov 13 2013