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A289817 Primes of the form k!3-9, where k!3 is the triple factorial number (A007661). 1
19, 71, 271, 3631, 58231, 209431, 4188791, 96342391, 17041023991, 72642169591, 2324549427191, 1143053268797439991, 52580450364682239991, 262134882788466687991, 694657439389436723199991, 38900816605808456499199991, 2295148179742698933452799991 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Price, Table of n, a(n) for n = 1..24

Henri & Renaud Lifchitz, PRP Records.Search for n!3-9.

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] - 9, {i, 5, 100}], PrimeQ[#]&]

CROSSREFS

Cf. A243078.

Sequence in context: A226802 A142516 A127874 * A321343 A255889 A154406

Adjacent sequences:  A289814 A289815 A289816 * A289818 A289819 A289820

KEYWORD

nonn

AUTHOR

Robert Price, Jul 12 2017

STATUS

approved

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Last modified March 4 07:23 EST 2021. Contains 341781 sequences. (Running on oeis4.)