OFFSET
1,2
COMMENTS
If k = 1 then n*2^n+1 is a Cullen prime (A050920).
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..10000
MATHEMATICA
Table[k = 1; While[! PrimeQ[k n*2^n + 1], k++]; k, {n, 80}] (* Michael De Vlieger, Jun 09 2017 *)
PROG
(PARI) a(n) = my(k=1); while (! isprime(k*n*2^n+1), k++); k; \\ Michel Marcus, Jun 07 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Jun 06 2017
STATUS
approved