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 A213301 #6 Sep 01 2012 09:12:14 %S A213301 373,3797,37337,37397,373379,831373,973373,3733739,8313733,9973331, %T A213301 9721373,52313797,73313797,97337333,99793373,373373977,831373379, %U A213301 799733317,974313797,991733137,7331337337,3797193373,9719337973,9917331373,9793733797,9974331373 %N A213301 Largest prime with n nonprime substrings (substrings with leading zeros are considered to be nonprime). %H A213301 Hieronymus Fischer, <a href="/A213301/b213301.txt">Table of n, a(n) for n = 0..25</a> %e A213301 a(0)=373, since 373 is the greatest prime such that all substrings are prime, hence it is the maximal prime with 0 nonprime substrings. %e A213301 a(3)= 37397, since the nonprime substrings of 37337 are 9, 39 and 7397, and all greater primes have > 3 nonprime substrings. %Y A213301 Cf. A019546, A035232, A039996, A046034, A069489, A085823, A211681, A211682, A211684, A211685. %Y A213301 Cf. A035244, A079307, A213300 - A213321. %K A213301 nonn,base %O A213301 0,1 %A A213301 _Hieronymus Fischer_, Aug 26 2012