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 A089130 #25 Oct 14 2024 01:36:24
%S A089130 2,13,61,2521,20161,3113510401,10461394944001,
%T A089130 132626429906095529318154240000001,
%U A089130 30207631531686917818677566034256998753632256000000001
%N A089130 Primes of the form (k! + 2)/2.
%H A089130 Vincenzo Librandi, <a href="/A089130/b089130.txt">Table of n, a(n) for n = 1..13</a>
%F A089130 a(n) = A139149(A082672(n)). - _Amiram Eldar_, Oct 13 2024
%t A089130 Select[Table[(n!+2)/2,{n,0,100}],PrimeQ] (* _Vincenzo Librandi_, Dec 07 2011 *)
%o A089130 (PARI) nfactp2d2(n) = { for(x=1,n, y=floor((x!+ 2)/2); if(isprime(y),print1(y",")) ) }
%o A089130 (Magma) [ a: n in [1..50] | IsPrime(a) where a is (Factorial(n)+2) div 2 ];
%Y A089130 Cf. A082672, A139149.
%K A089130 nonn
%O A089130 1,1
%A A089130 _Cino Hilliard_, Dec 05 2003