OFFSET
1,1
LINKS
H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.
H. Lifchitz, Mersenne and Fermat primes field
Index to primes in various ranges, form ((k+1)^n-1)/k
MATHEMATICA
Select[Prime[Range[100]], PrimeQ[(33^#-1)/32]&]
PROG
(PARI) isok(n) = isprime((33^n-1)/32); \\ Michel Marcus, Mar 13 2016
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Robert Price, Mar 05 2012
EXTENSIONS
a(5) corresponds to a probable prime discovered by Paul Bourdelais, Dec 31 2018
STATUS
approved