

A057469


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


26



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

1,1


LINKS

Table of n, a(n) for n=1..12.


MATHEMATICA

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


PROG

(PARI) is(n)=isprime(n) && ispseudoprime((2^n + 3^n)/5) \\ Charles R Greathouse IV, Apr 28 2015


CROSSREFS

Primes of form (3^n + 2^n)/5 are listed in A127908.
Sequence in context: A016081 A287301 A105762 * A247229 A082598 A082599
Adjacent sequences: A057466 A057467 A057468 * A057470 A057471 A057472


KEYWORD

nonn


AUTHOR

Robert G. Wilson v, Sep 09 2000


EXTENSIONS

More terms from Kamil Duszenko (kdusz(AT)wp.pl), Apr 11 2003
Definition corrected by Alexander Adamchuk, Feb 06 2007
New term 149497 found by JeanLouis Charton on Oct 14 2010 corresponding to a probable prime with 71328 digits. JeanLouis Charton, Oct 18 2010
New term 388897 found by JeanLouis Charton in Sep 18 2011 corresponding to a probable prime with 185551 digits.


STATUS

approved



