

A139065


Numbers k for which (7+k!)/7 is prime.


25



11, 15, 16, 25, 35, 59, 64, 68, 82, 121, 149, 238, 584, 912, 3349, 4111, 4324, 15314, 19944, 20658, 22740, 23364
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OFFSET

1,1


COMMENTS

For primes of the form (7+k!)/7, see A139064.
a(23) > 25000.  Robert Price, Nov 20 2016


LINKS

Table of n, a(n) for n=1..22.


MATHEMATICA

a = {}; Do[If[PrimeQ[(n! + 7)/7], AppendTo[a, n]], {n, 1, 500}]; a
Select[Range[500], PrimeQ[(7+#!)/7]&] (* Harvey P. Dale, Sep 01 2014 *)


PROG

(PARI) for(k=7, 1e3, if(ispseudoprime(k!/7+1), print1(k", "))) \\ Charles R Greathouse IV, Jul 15 2011


CROSSREFS

Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458.
Cf. n!/m1 is a prime: A002982, A082671, A139056, A139199A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10).
Sequence in context: A262721 A174952 A209898 * A186404 A111322 A069822
Adjacent sequences: A139062 A139063 A139064 * A139066 A139067 A139068


KEYWORD

nonn,hard,more


AUTHOR

Artur Jasinski, Apr 07 2008


EXTENSIONS

More terms from Serge Batalov, Feb 18 2015
a(18)a(22) from Robert Price, Nov 20 2016


STATUS

approved



