A289634 Primes of the form k!3-3, where k!3 is the triple factorial number (A007661).

7, 277, 877, 3637, 58237, 24344317, 17041023997, 44656330909544934316361777151999997, 3304568487306325139410771509247999997, 17994728558292550488813850298696914425610239999997, 2136063198892150618502015301628828867230815945271103455231999999997

Offset: 1

Author

Robert Price, Jul 12 2017

Keywords

• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..17
• Henri & Renaud Lifchitz, PRP Records.Search for n!3-3.
• Joe McLean, Interesting Sources of Probable Primes
• OpenPFGW Project, Primality Tester

Crossrefs

Cf. A242994.

Programs

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 3] - 3, {i, 4, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n,1,-3]-3,{n,2,200}],PrimeQ] (* Harvey P. Dale, Nov 25 2022 *)