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A076679 Numbers k such that 3*k! + 1 is prime. 9
2, 3, 4, 6, 7, 9, 10, 13, 23, 25, 32, 38, 40, 47, 96, 3442, 4048, 4522, 4887, 7033, 9528, 12915, 31762 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(24) > 50000. - Roger Karpin, Nov 13 2016

LINKS

Table of n, a(n) for n=1..23.

EXAMPLE

k = 6 is here because 3*6! + 1 = 2161 is prime.

PROG

(PARI) isok(n) = isprime(3*n! + 1); \\ Michel Marcus, Nov 13 2016

(PFGW) ABC2 3*$a!+1

a: from 1 to 1000 // Jinyuan Wang, Feb 05 2020

CROSSREFS

Cf. A002981, A051915, A076680, A076681, A076682, A076683, A178488, A180626, A126896.

Sequence in context: A088572 A071689 A187092 * A060233 A235203 A187102

Adjacent sequences:  A076676 A076677 A076678 * A076680 A076681 A076682

KEYWORD

nonn,more

AUTHOR

Phillip L. Poplin (plpoplin(AT)bellsouth.net), Oct 25 2002

EXTENSIONS

More terms from Serge Batalov, Feb 18 2015

a(20)-a(23) from Roger Karpin, Nov 13 2016

STATUS

approved

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Last modified May 28 17:37 EDT 2020. Contains 334684 sequences. (Running on oeis4.)