

A267943


Numbers n such that 2^n  3 and 3*2^n  1 are both prime.


0




OFFSET

1,1


COMMENTS

The intersection of A002235 and A050414 is not empty (3 does not belong to A267985).


LINKS

Table of n, a(n) for n=1..4.


FORMULA

A002235 INTERSECT A050414.


EXAMPLE

a(3) = 6 because 2^6  3 = 61 and 3*2^6  1 = 191 are both prime.


PROG

(MAGMA) [n: n in [2..94]  IsPrime(2^n3) and IsPrime(3*2^n1)];
(PARI) isok(n) = isprime(2^n3) && isprime(3*2^n1);


CROSSREFS

Cf. A002235, A007505, A050414, A050415, A238694, A267985.
Sequence in context: A263940 A256326 A239244 * A066466 A332511 A129293
Adjacent sequences: A267940 A267941 A267942 * A267944 A267945 A267946


KEYWORD

nonn,hard,more


AUTHOR

Arkadiusz Wesolowski, Jan 22 2016


STATUS

approved



