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A288155 Numbers k such that k!6 + 12 is prime, where k!6 is the sextuple factorial number (A085158 ). 1
0, 1, 5, 7, 11, 13, 17, 19, 23, 25, 41, 67, 71, 101, 109, 151, 163, 181, 233, 241, 265, 355, 433, 563, 767, 997, 1465, 1681, 1861, 1913, 2411, 2539, 2777, 13433, 22355, 30895, 44605 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Corresponding primes are: 13, 13, 17, 19, 67, 103, 947, 1741, 21517, 43237, 894930587, ...

a(37) > 50000.

Terms > 41 correspond to probable primes.

LINKS

Table of n, a(n) for n=1..37.

Henri & Renaud Lifchitz, PRP Records. Search for n!6+12.

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

EXAMPLE

11!6 + 12 = 11*5 + 12 = 67 is prime, so 11 is in the sequence.

MATHEMATICA

MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];

Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 12] &]

Select[Range[0, 45000], PrimeQ[Times @@ Range[#, 1, -6] + 12] &] (* Harvey P. Dale, Jul 09 2020 *)

CROSSREFS

Cf. A007661, A037082, A084438, A123910, A242994.

Sequence in context: A314294 A290729 A314295 * A135775 A353686 A219016

Adjacent sequences:  A288152 A288153 A288154 * A288156 A288157 A288158

KEYWORD

nonn,more

AUTHOR

Robert Price, Jun 05 2017

STATUS

approved

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Last modified May 20 07:54 EDT 2022. Contains 353852 sequences. (Running on oeis4.)