A289729 Primes of the form k!6-9, where k!6 is the sextuple factorial number (A085158).

7, 31, 631, 14071, 116471, 24663654391, 1282510028791, 17450008575991, 333247405883391991, 5444123475574783991

Offset: 1

Author

Robert Price, Jul 10 2017

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..18
• Henri & Renaud Lifchitz, PRP Records.Search for n!6-9.
• Joe McLean, Interesting Sources of Probable Primes
• OpenPFGW Project, Primality Tester

Crossrefs

Cf. A289687.

Programs

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 6] - 9, {i, 8, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n,1,-6]-9,{n,8,100}],PrimeQ] (* Harvey P. Dale, Aug 21 2023 *)