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 A303738 #5 Jun 06 2018 03:33:59 %S A303738 2,40343,371993326789901217467999454553208905727999 %N A303738 Primes of form (2*k)! + k! - 1. %C A303738 a(4) has 154 digits and is too large to be included. %F A303738 a(n) = (2*A303737(n))! + A303737(n)! - 1. %p A303738 f:=factorial: select(isprime,[seq(f(2*k)+f(k)-1,k=1..600)]); %Y A303738 Cf. A242487, A300947, A303737. %K A303738 nonn %O A303738 1,1 %A A303738 _Muniru A Asiru_, May 27 2018