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A076681 Numbers k such that 5*k! + 1 is prime. 7
2, 3, 5, 10, 11, 12, 17, 34, 74, 136, 155, 259, 271, 290, 352, 479, 494, 677, 776, 862, 921, 932, 2211, 3927, 4688 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(26) > 4700. - Jinyuan Wang, Feb 04 2020

LINKS

Table of n, a(n) for n=1..25.

EXAMPLE

k = 3 is here because 5*3! + 1 = 31 is prime.

PROG

(PARI) is(k) = ispseudoprime(5*k!+1); \\ Jinyuan Wang, Feb 04 2020

CROSSREFS

Cf. A002981, A051915, A076679, A076680, A076682, A076683, A178488, A180626, A126896.

Sequence in context: A288244 A246392 A219860 * A047604 A104427 A259732

Adjacent sequences:  A076678 A076679 A076680 * A076682 A076683 A076684

KEYWORD

nonn,more

AUTHOR

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

EXTENSIONS

a(25) from Jinyuan Wang, Feb 04 2020

STATUS

approved

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Last modified May 31 02:51 EDT 2020. Contains 334747 sequences. (Running on oeis4.)