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A288449 Numbers k such that k!6 + 36 is prime, where k!6 is the sextuple factorial number (A085158 ). 1
1, 5, 7, 13, 17, 25, 29, 31, 55, 77, 119, 311, 373, 587, 1037, 1057, 1645, 2279, 2327, 2531, 2893, 2917, 3293, 3799, 9139, 14131, 14405, 15041, 24923, 26563, 48743 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Corresponding primes are: 37, 41, 43, 127, 971, 43261, 623681, 1340011, 5745471106411, ...

a(32) > 50000.

Terms > 31 correspond to probable primes.

LINKS

Table of n, a(n) for n=1..31.

Henri & Renaud Lifchitz, PRP Records. Search for n!6+36.

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

EXAMPLE

13!6 + 36 = 13*7*1 + 36 = 127 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] + 36] &]

CROSSREFS

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

Sequence in context: A317543 A253297 A163385 * A178218 A314323 A314324

Adjacent sequences:  A288446 A288447 A288448 * A288450 A288451 A288452

KEYWORD

nonn,more

AUTHOR

Robert Price, Jun 09 2017

STATUS

approved

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Last modified November 18 14:37 EST 2019. Contains 329262 sequences. (Running on oeis4.)