A289823 Primes of the form k!3-6561, where k!3 is the triple factorial number (A007661).

51679, 202879, 4182239, 608601439, 2504895839, 81359229945439, 664565853945439, 262134882788466681439, 2103662445439858602854085842728187330559993439, 17994728558292550488813850298696914425610239993439

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..13

Henri & Renaud Lifchitz, PRP Records.Search for n!3-6561.

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] - 6561, {i, 14, 100}], PrimeQ[#]&]

Crossrefs

Cf. A261344.

Sequence in context: A344644 A344645 A203354 * A147530 A184454 A003134

Adjacent sequences: A289820 A289821 A289822 * A289824 A289825 A289826

Keyword

nonn

Author

Robert Price, Jul 12 2017

Status

approved