1,1

If k = 1 then n*2^n-1 is a Woodall prime (A050918).

Pierre CAMI, Table of n, a(n) for n = 1..10000

Table[k = 1; While[! PrimeQ[k n*2^n - 1], k++]; k, {n, 78}] (* Michael De Vlieger, Jun 07 2017 *)

(PARI) a(n) = my(k=1); while(1, if(ispseudoprime(k*n*2^n-1), return(k)); k++) \\ Felix Fröhlich, Jun 06 2017

Cf. A050918.

Sequence in context: A153452 A090680 A133771 * A319522 A217612 A029254

Adjacent sequences: A288155 A288156 A288157 * A288159 A288160 A288161

nonn

Pierre CAMI, Jun 06 2017

approved