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 A213305 #15 Oct 24 2014 04:14:23 %S A213305 2,13,11,127,103,101,1013,1019,1021,1009,10177,10037,10067,10007, %T A213305 10009,100237,100271,100153,100043,100003,100049,1001173,1000313, %U A213305 1000037,1000033,1000039,1000003,1000081,10000379,10001237,10000223 %N A213305 Minimal prime with n nonprime substrings (Version 1: substrings with leading zeros are considered to be nonprime). %H A213305 Hieronymus Fischer, <a href="/A213305/b213305.txt">Table of n, a(n) for n = 0..100</a> %F A213305 a(n) > 10^floor((sqrt(8*n+1)-1)/2) for n>0. %F A213305 a(m(m+1)/2) > 10^m, m>0. %F A213305 a(n) >= A213302(n). %e A213305 a(0) = 2, since 2 is the least prime with zero nonprime substrings. %e A213305 a(1) = 13, since 13 is the least prime with exactly 1 (“1”) nonprime substrings. %e A213305 a(2) = 11, since 11 is the least prime with exactly 2 (“1” and “1”) nonprime substrings. %Y A213305 Cf. A019546, A035232, A039996, A046034, A069489, A085823, A211681, A211682, A211684, A211685. %Y A213305 Cf. A035244, A079307, A213300 - A213321. %K A213305 nonn,base %O A213305 0,1 %A A213305 _Hieronymus Fischer_, Aug 26 2012