

A201357


Numbers n such that (2^n + n + 1)*2^n  1 is prime.


7




OFFSET

1,2


LINKS

Table of n, a(n) for n=1..7.


EXAMPLE

13 is in the sequence because (2^13 + 13 + 1)*2^13  1 = 67223551 is prime.


MATHEMATICA

lst={}; Do[If[PrimeQ[(2^n + n+1)*2^n1], AppendTo[lst, n]], {n, 10000}]; lst


PROG

(PARI) is(n)=isprime((2^n+n+1)<<n1) \\ Charles R Greathouse IV, Feb 17 2017


CROSSREFS

Cf. A201356, A201358, A201359, A201360, A201361, A201362, A201363.
Sequence in context: A197097 A064962 A242562 * A220551 A185073 A185193
Adjacent sequences: A201354 A201355 A201356 * A201358 A201359 A201360


KEYWORD

nonn,hard


AUTHOR

Michel Lagneau, Nov 30 2011


STATUS

approved



