

A125957


Numbers n such that (2^n + 11^n)/13 is prime.


4




OFFSET

1,1


COMMENTS

All terms are primes. Corresponding primes of the form (2^n + 11^n)/13 are {103, 12391, 38880540653801911, ...}.
a(11) > 10^5.  Robert Price, Feb 26 2013


LINKS

Table of n, a(n) for n=1..10.


MATHEMATICA

Do[p=Prime[n]; f=(2^p+11^p)/13; If[PrimeQ[f], Print[{p, f}]], {n, 1, 100}]


PROG

(PARI) is(n)=ispseudoprime((2^n+11^n)/13) \\ Charles R Greathouse IV, Feb 20 2017


CROSSREFS

Cf. A000978 = numbers n such that (2^n + 1)/3 is prime. Cf. A057469 = numbers n such that (2^n + 3^n)/5 is prime. Cf. A082387 = numbers n such that (2^n + 5^n)/7 is prime.
Sequence in context: A265425 A256438 A251737 * A259908 A137460 A319908
Adjacent sequences: A125954 A125955 A125956 * A125958 A125959 A125960


KEYWORD

hard,more,nonn


AUTHOR

Alexander Adamchuk, Feb 06 2007


EXTENSIONS

2 more terms from Ryan Propper, Feb 09 2008
a(9)a(10) from Robert Price, Feb 26 2013


STATUS

approved



