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 A086158 #3 Oct 01 2013 17:57:41
%S A086158 3,5,35,3511,351117,35111729,3511172941,351117294159,35111729415971,
%T A086158 35111729415971101,35111729415971101107,35111729415971101107137,
%U A086158 35111729415971101107137149,35111729415971101107137149179
%N A086158 Concatenation of the smaller members of first n pairs of twin primes.
%o A086158 (PARI) concattwprl(n) = { y=3; print1(3","5","); forprime(x=5,n, if(isprime(x+2), y=eval(concat(Str(y),Str(x))); print1(y",") ) ) }
%K A086158 nonn,base
%O A086158 2,1
%A A086158 _Cino Hilliard_, Sep 08 2003