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 A238011 #8 Dec 23 2024 21:49:47 %S A238011 5,7,8,15,103,179,473,2054,3595,4039 %N A238011 Numbers k such that (2k)! - k! - 1 is prime. %C A238011 No more terms up to 5000. The first six terms are as previously stated in A118813. All terms found and primes proved by OpenPFGW. %C A238011 No more terms up to 10000. - _Michael S. Branicky_, Dec 23 2024 %H A238011 The OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">OpenPFGW</a> %e A238011 5 is a term because (2*5)! - 5! - 1 = 3628679 is prime. %e A238011 4039 is a term because (2*4039)! - 4039! - 1 is prime (28058 digits). %Y A238011 Cf. A118813 (corresponding primes), A237443, A118812. %K A238011 nonn,hard,more %O A238011 1,1 %A A238011 _Rick L. Shepherd_, Feb 16 2014