

A057469


Prime numbers k such that (2^k + 3^k)/5 is prime.


26



3, 7, 11, 83, 149, 223, 599, 647, 1373, 8423, 149497, 388897, 531611, 2052329
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OFFSET

1,1


LINKS



MATHEMATICA

Do[ If[ PrimeQ[ n ], If[ PrimeQ[ (3^n + 2^n)/5 ], Print[ n ] ] ], {n, 0, 6270} ]


PROG

(Magma) [p: p in [3..1000]  IsPrime(p) and IsPrime((2^p + 3^p) div 5)]; // Jinyuan Wang, Dec 22 2019


CROSSREFS

Cf. A127908 (primes of the form (3^k+2^k)/5).


KEYWORD

nonn,more


AUTHOR



EXTENSIONS

More terms from Kamil Duszenko (kdusz(AT)wp.pl), Apr 11 2003
a(11) corresponding to a probable prime with 71328 digits from JeanLouis Charton, Oct 14 2010
a(12) corresponding to a probable prime with 185551 digits from JeanLouis Charton, Sep 18 2011
a(13) corresponding to a probable prime with 253643 digits from Ryan Propper, Dec 10 2023
a(14) corresponding to a probable prime with 979210 digits from Ryan Propper, Dec 10 2023


STATUS

approved



