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 A133986 #6 Mar 31 2012 10:32:41 %S A133986 23,53,3137,5347,5953,6761,8389,137131,151157,157163,167173,179173, %T A133986 199211,211199,223211,233239,239233,257263,263257,263269,271277, %U A133986 331337,353359,359353,373379,433439,467479,509521,523541,541523,541547,593587 %N A133986 Consecutive prime pairs which after concatenation are prime (ascending or descending order). %C A133986 For the range above the prime concatenations occur after a mean of 3.1579 trials. Some primes are interlocking, as many as three in succession. %F A133986 Select consecutive prime pairs, concatenate and test for primality (ascending and descending order) %e A133986 5347 is a member: 53 and 47, prime; 4753 was also tested, but is composite. %Y A133986 Cf. A088784. %K A133986 easy,nonn,base %O A133986 1,1 %A A133986 _Enoch Haga_, Sep 30 2007 %E A133986 Edited by _Charles R Greathouse IV_, Apr 26 2010