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 A290121 #20 Apr 16 2025 10:57:16
%S A290121 2,89,5039,453599,4989599,2615348735999,15205637551103999,
%T A290121 32327905188896022580370544394201497496149704048639999999999,
%U A290121 68043117384680383000466155030980344080536633048599859316607515858708885143551999999999999999
%N A290121 Primes of the form k!/8 - 1.
%H A290121 Robert Price, <a href="/A290121/b290121.txt">Table of n, a(n) for n = 1..9</a>
%H A290121 Joe McLean, <a href="http://web.archive.org/web/20091027034731/http://uk.geocities.com/nassarawa%40btinternet.com/probprim2.htm">Interesting Sources of Probable Primes</a>.
%H A290121 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>.
%F A290121 a(n) = A139183(A139203(n)). - _Elmo R. Oliveira_, Apr 16 2025
%t A290121 Select[Table[k! / 8 - 1, {k, 4, 100}], PrimeQ[#]&]
%Y A290121 Cf. A139183, A139203.
%K A290121 nonn
%O A290121 1,1
%A A290121 _Robert Price_, Jul 19 2017
%E A290121 Missing terms inserted by _Alois P. Heinz_, Dec 05 2024