A288879 - OEIS

A288879

Primes of the form k!3 + 3^3, where k!3 is the triple factorial number (A007661).

%I #5 Jun 18 2017 22:06:34

%S 29,31,37,107,307,907,12347,4188827,96342427,2324549427227,

%T 17961239296027,52580450364682240027,262134882788466688027,

%U 142299187144047333874073600027,1414585397090614713326770033423904956109645017737276725445918510284800000000027

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

%H Robert Price, <a href="/A288879/b288879.txt">Table of n, a(n) for n = 1..19</a>

%H Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3+3^3&action=Search">PRP Records.Search for n!3+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] + 3^3, {i, 0, 100}], PrimeQ[#]&]

%Y Cf. A247886.

%K nonn

%O 1,1

%A _Robert Price_, Jun 18 2017