

A230809


Primes p of the form 60*n + 59 such that 2*p + 1 is also prime.


3



179, 239, 359, 419, 659, 719, 1019, 1439, 1499, 1559, 2039, 2339, 2399, 2459, 2699, 2819, 2939, 3299, 3359, 3539, 3779, 4019, 4919, 5039, 5279, 5399, 5639, 6899, 7079, 9059, 9419, 9479, 9539, 10799, 11519, 11579, 11699, 11939, 12119, 12899, 12959, 13619
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OFFSET

1,1


COMMENTS

Primes p such that 2*p + 1 divides Lucas(p) and Mersenne(p).


LINKS

Table of n, a(n) for n=1..42.
Eric Weisstein's World of Mathematics, Lucas Number
Eric Weisstein's World of Mathematics, Mersenne Number


FORMULA

A005384 INTERSECT A142799.
A002515 INTERSECT A215850.


EXAMPLE

179 is in the sequence since it is prime and 359 is a factor of both Lucas(179) and Mersenne(179) = 2^179  1.


PROG

(MAGMA) [p : p in [59..13619 by 60]  IsPrime(p) and IsPrime(2*p+1)];
(PARI) forstep(p=59, 13619, 60, if(isprime(p)&&isprime(2*p+1), print1(p, ", ")));


CROSSREFS

Subsequence of A142799, of A215850, and of A239548. Cf. A000032, A001348, A002515.
Sequence in context: A226928 A162164 A238893 * A142028 A146359 A142441
Adjacent sequences: A230806 A230807 A230808 * A230810 A230811 A230812


KEYWORD

nonn


AUTHOR

Arkadiusz Wesolowski, Oct 30 2013


STATUS

approved



