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 A130060 #6 Mar 31 2012 14:47:12
%S A130060 2,3,7,179,619,17807
%N A130060 Primes p such that p^2 divides 3^p - 2^p - 1; or primes in A127074(n).
%C A130060 The prime p divides 3^p - 2^p - 1. Quotients (3^p - 2^p - 1)/p, where p = Prime[n], are listed in A127071. - _Alexander Adamchuk_, Jan 31 2008
%C A130060 a(7) > 10^9. [From _D. S. McNeil_, Mar 16 2009]
%t A130060 Do[ n=Prime[k]; f=PowerMod[3,n,n^2] - PowerMod[2,n,n^2] - 1; If[ IntegerQ[ f/n^2 ], Print[n] ], {k,1,100000} ]
%Y A130060 Cf. A127071, A127072, A127073, A127074 = numbers n such that n^2 divides 3^n - 2^n - 1. Cf. A130058, A130059, A130061, A130062, A130063.
%K A130060 hard,more,nonn
%O A130060 1,1
%A A130060 _Alexander Adamchuk_, May 05 2007
%E A130060 2 more terms found by Ryan Propper, Jan 01 2008.
%E A130060 Incorrect a(7), a(8) removed by _D. S. McNeil_, Mar 16 2009. (The old version was 2,3,7,179,619,17807,135433,1376257.)