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 A138942 #4 Jul 22 2012 15:48:59
%S A138942 17,48871,72155888332711,
%T A138942 5612879326907642747716598753475172001050151332970028230897946300714884208847
%N A138942 Primes of the form (14^n - 3^n)/11.
%t A138942 a={};Do[p=(14^n-3^n)/11;If[PrimeQ[p],AppendTo[a,p]],{n,1,10^2}];a
%t A138942 Select[Table[(14^n-3^n)/11,{n,1000}],PrimeQ] (* _Harvey P. Dale_, Jul 22 2012 *)
%Y A138942 Cf. A128029.
%K A138942 nonn
%O A138942 1,1
%A A138942 _Vladimir Joseph Stephan Orlovsky_, May 16 2008