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A288444 Numbers k such that k!6 + 16 is prime, where k!6 is the sextuple factorial number (A085158 ). 1
1, 3, 7, 9, 11, 13, 15, 21, 23, 35, 37, 39, 47, 49, 59, 111, 117, 163, 287, 311, 601, 635, 855, 895, 2455, 2929, 3369, 7147, 10367, 12311, 13093, 13611, 14431, 17305, 27331 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Corresponding primes are: 17, 19, 23, 43, 71, 107, 421, 8521, 21521, 21827591, 49579091, 295540261, 42061737041, 104463111041, ...

a(36) > 50000.

Terms > 49 correspond to probable primes.

LINKS

Table of n, a(n) for n=1..35.

Henri & Renaud Lifchitz, PRP Records. Search for n!6+16.

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

EXAMPLE

11!6 + 16 = 11*5 + 16 = 71 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] + 16] &]

CROSSREFS

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

Sequence in context: A165631 A245586 A005818 * A085820 A045572 A069254

Adjacent sequences:  A288441 A288442 A288443 * A288445 A288446 A288447

KEYWORD

nonn,more

AUTHOR

Robert Price, Jun 09 2017

STATUS

approved

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Last modified November 17 00:02 EST 2018. Contains 317275 sequences. (Running on oeis4.)