A289634 - OEIS

%I #22 Nov 25 2022 11:32:34

%S 7,277,877,3637,58237,24344317,17041023997,

%T 44656330909544934316361777151999997,

%U 3304568487306325139410771509247999997,17994728558292550488813850298696914425610239999997,2136063198892150618502015301628828867230815945271103455231999999997

%N Primes of the form k!3-3, where k!3 is the triple factorial number (A007661).

%H Robert Price, <a href="/A289634/b289634.txt">Table of n, a(n) for n = 1..17</a>

%H Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3-3&amp;action=Search">PRP Records.Search for n!3-3.</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, 3] - 3, {i, 4, 100}], PrimeQ[#]&]

%t Select[Table[Times@@Range[n,1,-3]-3,{n,2,200}],PrimeQ] (* _Harvey P. Dale_, Nov 25 2022 *)

%Y Cf. A242994.

%K nonn

%O 1,1

%A _Robert Price_, Jul 12 2017