A288614 - OEIS

A288614

Primes of the form k!6+18, where k!6 is the sextuple factorial number (A085158).

%I #9 Dec 14 2021 17:44:06

%S 19,23,73,109,953,1747,21523,1339993,49579093,894930593,104463111043,

%T 3879320022245629336393,131181879631714694053764558690643,

%U 5685668465320307573857236025777988251766371484393,164577616892349380880997566903814398769391101461559752758998046893

%N Primes of the form k!6+18, where k!6 is the sextuple factorial number (A085158).

%H Robert Price, <a href="/A288614/b288614.txt">Table of n, a(n) for n = 1..15</a>

%H Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n6+18&action=Search">PRP Records.Search for n!6+18.</a>

%H 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 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>

%t MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];

%t Select[Table[MultiFactorial[i, 6] + 18, {i, 0, 100}], PrimeQ[#]&]

%t Select[Table[(Times@@Range[k,1,-6])+18,{k,250}],PrimeQ] (* _Harvey P. Dale_, Dec 14 2021 *)

%Y Cf. A288445.

%K nonn

%O 1,1

%A _Robert Price_, Jun 11 2017