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 A166339 #2 Oct 02 2013 16:01:16
%S A166339 1,2,2016,3226,8130
%N A166339 Numbers n such that Sum(n!/k!),k=0..n is prime.
%C A166339 No further terms up to n=20000. The sequence a[n]=Sum(n!/k!),k=0..n is A000522.
%F A166339 n is an index of the sequence a[n]=Sum(n!/k!),k=0..n such that a[n] is prime.
%e A166339 For n=2, a[2]=5 which is a prime.
%o A166339 (PARI) a=1;for(n=1,20000,a=n*a+1;if(ispseudoprime(a,0),print("n="n)));
%Y A166339 Cf. A000522 (corresponding sequence).
%K A166339 nonn
%O A166339 1,2
%A A166339 _Mike Oakes_, Oct 12 2009