A289818 Primes of the form k!3-27, where k!3 is the triple factorial number (A007661).

53, 853, 3613, 24344293, 72642169573, 2576442067869429759973, 38900816605808456499199973, 26070192823309041523916799973, 17978533302590087193373917833428087202627190783999999973

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..21

Henri & Renaud Lifchitz, PRP Records.Search for n!3-27.

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, 3] - 27, {i, 7, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n, 1, -3]-27, {n, 7, 150}], PrimeQ] (* Harvey P. Dale, Mar 08 2020 *)

Crossrefs

Cf. A247463.

Sequence in context: A201153 A077794 A200532 * A253111 A157618 A093982

Adjacent sequences: A289815 A289816 A289817 * A289819 A289820 A289821

Keyword

nonn

Author

Robert Price, Jul 12 2017

Status

approved