A289758 Primes of the form k!5-1, where k!5 is the quintuple factorial number (A085157).

2, 3, 5, 13, 23, 167, 311, 503, 1696463, 3616703, 119351231, 393749999, 388856692223, 35437499999999, 728640635326636031, 3885182313590882303, 19837740893195045044223, 5126863427472785697108393983, 140901732869280543971697196500573487103

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..27

Henri & Renaud Lifchitz, PRP Records.Search for n!5-1.

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 5] - 1, {i, 2, 100}], PrimeQ[#]&]

Crossrefs

Cf. A085149.

Sequence in context: A215306 A072537 A357916 * A089477 A099962 A173718

Adjacent sequences: A289755 A289756 A289757 * A289759 A289760 A289761

Keyword

nonn

Author

Robert Price, Jul 11 2017

Status

approved