A288718 Primes of the form k!5+1, where k!5 is the quintuple factorial number (A085157).

2, 3, 5, 7, 37, 67, 313, 751, 2857, 129169, 576577, 17873857, 54286849, 393750001, 643458817, 19053977918977, 206180145819649, 11716249122484566383298871297, 177636555893291390456871518209, 49055724379818682505120501943238657

Offset: 1

Author

Robert Price, Jun 13 2017

Keywords

• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..28
• Henri& Renaud Lifchitz, PRP Records.Search for n!5+1.
• Joe McLean, Interesting Sources of Probable Primes
• OpenPFGW Project, Primality Tester

Crossrefs

Cf. A085148.

Programs

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 5] + 1, {i, 0, 100}], PrimeQ[#]&]