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 A068103 #18 Oct 19 2017 10:43:03
%S A068103 2,2,223,2221,22229,2222203,22222223,22222223,222222227,22222222223,
%T A068103 22222222223,2222222222243,22222222222201,22222222222229,
%U A068103 222222222222227,222222222222222043,222222222222222221
%N A068103 Smallest prime starting with at least n 2s.
%H A068103 M. F. Hasler, <a href="/A068103/b068103.txt">Table of n, a(n) for n = 0..500</a>
%o A068103 (PARI) A068103(n)={n=10^n\9*2;n>2&for(d=1,9e9,n*=10;for(t=1,10^d-1,ispseudoprime(n+t)&return(n+t)));2} \\ - _M. F. Hasler_, Oct 17 2012
%Y A068103 Cf. A065585, A065584, A068104, A068105.
%K A068103 base,nonn
%O A068103 0,1
%A A068103 _Amarnath Murthy_, Feb 20 2002
%E A068103 More terms from _Sascha Kurz_, Mar 19 2002
%E A068103 Corrected by _Don Reble_, Jan 17 2007