A046845 Numbers n such that n*2^n+(n+1) is prime.

2, 38, 426, 978, 1530, 5268, 7238, 8384, 9696, 11930, 16164, 40502

Offset

1,1

Comments

a(6) (if it exists) > 4000. - Hiroaki Yamanouchi, Sep 22 2014

a(13) > 200000. - Giovanni Resta, May 01 2016

Links

Table of n, a(n) for n=1..12.

Mathematica

Select[Range[10^4], PrimeQ[#*2^# + (# + 1)] &] (* Michael De Vlieger, Mar 02 2015 *)

Prog

(PARI) for(n=1, 10^6, if(ispseudoprime(n*2^n+(n+1)), print1(n, ", "))); \\ Joerg Arndt, Mar 02 2015

Crossrefs

Cf. A046844 (corresponding primes).

Sequence in context: A179503 A126731 A216357 * A098772 A207320 A262585

Adjacent sequences: A046842 A046843 A046844 * A046846 A046847 A046848

Keyword

hard,more,nonn

Author

Felice Russo

Extensions

a(4)-a(5) from Hiroaki Yamanouchi, Sep 22 2014

New name from Hiroaki Yamanouchi, Sep 22 2014

Term a(6)-a(10) (pseudoprimes) from Joerg Arndt, Mar 02 2015

a(11)-a(12) (pseudoprimes) from Giovanni Resta, May 01 2016

Status

approved