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A289700 Numbers k such that k!6 - 36 is prime, where k!6 is the sextuple factorial number (A085158). 1
11, 19, 25, 55, 61, 113, 131, 133, 439, 529, 1079, 1621, 2609, 2825, 3997, 4235, 5081, 7319, 8365, 9023, 10273, 18095, 18199, 22625, 24535, 27229, 28883, 99877 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Corresponding primes are: 19, 1693, 43189, 5745471106339, 350473737488839, ...

a(29) > 10^5.

Terms > 25 correspond to probable primes.

LINKS

Table of n, a(n) for n=1..28.

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

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

EXAMPLE

19!6 - 36 = 19*13*7*1 - 36 = 1693 is prime, so 19 is in the sequence.

MATHEMATICA

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

Select[Range[10, 50000], PrimeQ[MultiFactorial[#, 6] - 36] &]

CROSSREFS

Cf. A007661, A037082, A084438, A085158, A123910, A242994.

Sequence in context: A089172 A152567 A029481 * A231012 A231007 A129916

Adjacent sequences:  A289697 A289698 A289699 * A289701 A289702 A289703

KEYWORD

nonn,more

AUTHOR

Robert Price, Jul 09 2017

EXTENSIONS

a(28) from Robert Price, Nov 28 2018

STATUS

approved

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Last modified October 24 20:35 EDT 2021. Contains 348233 sequences. (Running on oeis4.)