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A138050
Numbers k such that 23^k + 2 is prime.
7
0, 11, 39, 323, 12415, 14655, 27679
OFFSET
1,2
COMMENTS
No further terms < 100000. - Ray Chandler, Aug 03 2011
LINKS
Henri & Renaud Lifchitz, PRP Records.
MATHEMATICA
Do[ f = 23^n + 2; If[ PrimeQ[ f ], Print[ {n, f} ] ], {n, 1, 323} ]
PROG
(PARI) is(n)=ispseudoprime(23^n+2) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
Cf. A051783 (k such that 3^k + 2 is prime).
Cf. A087885 (k such that 5^k + 2 is prime).
Sequence in context: A336901 A173373 A127867 * A341232 A183940 A335077
KEYWORD
nonn,more
AUTHOR
Alexander Adamchuk, Mar 02 2008
EXTENSIONS
a(5)-a(7) from Ray Chandler, Aug 01 2011
STATUS
approved