A289550 Primes of the form k!6-4, where k!6 is the sextuple factorial number (A085158).

2, 3, 23, 401, 8501, 229631, 623641

Offset

1,1

Comments

The next term is too large to display.

The next term (a(8)) has 113 digits. - Harvey P. Dale, Dec 09 2020

Links

Robert Price, Table of n, a(n) for n = 1..10

Henri & Renaud Lifchitz, PRP Records.Search for n!6-4.

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, 6] - 4, {i, 4, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n, 1, -6]-4, {n, 3, 100}], PrimeQ] (* Harvey P. Dale, Dec 09 2020 *)

Crossrefs

Cf. A289547.

Sequence in context: A064888 A104458 A191859 * A154553 A160341 A092388

Adjacent sequences: A289547 A289548 A289549 * A289551 A289552 A289553

Keyword

nonn

Author

Robert Price, Jul 07 2017

Status

approved