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 A289858 #8 Apr 16 2025 09:04:03
%S A289858 9371,34458401,191898783962509601,319830986772877770814601,
%T A289858 157952079428395476360490147277858351,
%U A289858 2987435000850314871976096554696085799164511452611632783323554397412108351,283806325080779912837729172696128150920628587998105114415737667754150389601
%N A289858 Primes of the form k!2 - 1024, where k!2 is the double factorial number (A006882).
%H A289858 Robert Price, <a href="/A289858/b289858.txt">Table of n, a(n) for n = 1..7</a>
%H A289858 Henri and Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n2-1024&action=Search">PRP Records.Search for n!2-1024</a>.
%H A289858 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 A289858 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>.
%F A289858 a(n) = A006882(A258866(n)) - 1024. - _Elmo R. Oliveira_, Apr 15 2025
%t A289858 MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t A289858 Select[Table[MultiFactorial[i, 2] - 1024, {i, 10, 100}], PrimeQ[#]&]
%Y A289858 Cf. A006882, A258866.
%K A289858 nonn
%O A289858 1,1
%A A289858 _Robert Price_, Jul 13 2017