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 A116897 #13 Nov 15 2024 14:27:03 %S A116897 4,6,8,14,18,28,64,324,778,882 %N A116897 Numbers k such that k! - k!! + 1 is prime, where k!! denotes double factorial (A006882). %C A116897 Next term is greater than 3000. %C A116897 Next term is greater than 15000. - _Michael S. Branicky_, Nov 15 2024 %e A116897 6! - 6!! + 1 = 673, which is prime. %t A116897 Select[Range[900],PrimeQ[#!-#!!+1]&] (* _Harvey P. Dale_, Mar 27 2015 *) %Y A116897 Cf. A000142, A006882, A116896. %K A116897 hard,more,nonn %O A116897 1,1 %A A116897 _Giovanni Resta_, Mar 04 2006