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 A123910 #19 Aug 30 2021 04:05:40
%S A123910 5,7,9,11,13,15,19,25,35,79,81,105,171,243,271,295,355,523,591,1211,
%T A123910 3073,11157,12887,19825
%N A123910 Numbers k such that k!!-4 is prime.
%C A123910 Corresponding primes of the form k!!-4 = a(n)!!-4 are {11, 101, 941, 10391, 135131, 2027021, 654729071, 7905853580621, 221643095476699771871, ...}.
%C A123910 a(25) > 50000. - _Robert Price_, May 08 2015
%H A123910 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>
%t A123910 Do[f=n!!-4;If[PrimeQ[f],Print[{n,f}]],{n,1,355}]
%Y A123910 Cf. A007749, A094144.
%K A123910 hard,more,nonn
%O A123910 1,1
%A A123910 _Alexander Adamchuk_, Oct 28 2006
%E A123910 More terms from _Farideh Firoozbakht_, Nov 19 2006
%E A123910 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008
%E A123910 a(23)-a(24) from _Robert Price_, May 08 2015