A046849 Numbers k such that k*2^k+(k-1) is prime.

1, 4, 6, 30, 34, 94, 216, 1120, 1438, 3370, 5062, 6714, 30666, 36966

Offset

1,2

Comments

The corresponding primes are given in A046848.

Links

Table of n, a(n) for n=1..14.

Mathematica

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

Prog

(PARI) isok(n) = isprime(n*2^n+(n-1)); \\ Michel Marcus, Oct 12 2014
(PARI) for(n=1, 10^6, if(ispseudoprime(n*2^n+(n-1)), print1(n, ", "))); \\ Joerg Arndt, Mar 02 2015

Crossrefs

Cf. A046848.

Sequence in context: A259087 A364737 A056221 * A090530 A154667 A093121

Adjacent sequences: A046846 A046847 A046848 * A046850 A046851 A046852

Keyword

hard,more,nonn

Author

Felice Russo

Extensions

a(8)-a(9) from Michel Marcus, Oct 12 2014

a(10)-a(12) (pseudoprimes) from Joerg Arndt, Mar 02 2015

a(13)-a(14) from Michael S. Branicky, Jan 21 2023

Status

approved