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 A090703 #27 Jun 12 2025 03:38:18
%S A090703 1,2,3,4,5,7,12,19,23,45,58,149,151,197,682,879,1134,1906,6616,10242,
%T A090703 12015
%N A090703 Numbers k such that k*k! + 1 is prime.
%F A090703 a(n) = A049432(n) - 1.
%e A090703 3*3! + 1 = 19 and 19 is prime, so 3 is a member.
%t A090703 Do[If[PrimeQ[n*n! + 1], Print[n]], {n, 0, 2000}] (* Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), May 05 2006 *)
%o A090703 (PARI) isok(k) = ispseudoprime(k*k! + 1); \\ _Altug Alkan_, Mar 22 2018
%Y A090703 Cf. A049432.
%K A090703 nonn,more
%O A090703 1,2
%A A090703 mohammed bouayoun (bouyao(AT)wanadoo.fr), Jan 15 2004
%E A090703 a(17) from Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), May 05 2006
%E A090703 a(18)-a(19) from _Jason Earls_, Jan 24 2008
%E A090703 a(20) from _Seiichi Manyama_ (by using the data calculated by _Donovan Johnson_, Dec 18 2009), Mar 22 2018
%E A090703 a(21) from _Michael S. Branicky_, Jun 11 2025