

A093793


Numbers n such that 5^n+4^(n1) is prime.


19



2, 6, 22, 94, 622, 910, 1058, 1306, 4430, 18914, 23654, 35630, 52846, 63498, 85630
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OFFSET

1,1


COMMENTS

a(16) > 10^5.  Robert Price, Mar 08 2016


LINKS

Table of n, a(n) for n=1..15.


EXAMPLE

22 is a member since 522+421 = 2388583837526729 which is a prime number.


MATHEMATICA

Do[ If[ PrimeQ[5^n + 4^(n  1)], Print[n]], {n, 5000}]


PROG

(PARI) is(n)=isprime(5^n+4^(n1)) \\ Charles R Greathouse IV, Feb 17 2017


CROSSREFS

Cf. A082103, A093717, A093765, A096185, A093794, A093795, A096186.
Sequence in context: A187251 A193763 A301385 * A087959 A292096 A006871
Adjacent sequences: A093790 A093791 A093792 * A093794 A093795 A093796


KEYWORD

nonn


AUTHOR

Herman H. Rosenfeld (herm3(AT)pacbell.net), May 17 2004


EXTENSIONS

More terms from Robert G. Wilson v, Jun 18 2004
a(10)a(15) from Robert Price, Mar 08 2016


STATUS

approved



