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A289818 Primes of the form k!3-27, where k!3 is the triple factorial number (A007661). 1
53, 853, 3613, 24344293, 72642169573, 2576442067869429759973, 38900816605808456499199973, 26070192823309041523916799973, 17978533302590087193373917833428087202627190783999999973 (list; graph; refs; listen; history; text; internal format)
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

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Last modified March 4 07:10 EST 2021. Contains 341781 sequences. (Running on oeis4.)