OFFSET
1,2
COMMENTS
a(15) > 10^10. - Giovanni Resta, May 23 2013
EXAMPLE
The 25th prime is 97, and 97 divides 2^(25-1) + 1 = 16777217, so 25 is in the sequence.
MATHEMATICA
Select[Range[10^6], (p = Prime[#]; PowerMod[2, # - 1, p] == p - 1) &] (* Giovanni Resta, May 23 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Gerasimov Sergey, May 23 2013
EXTENSIONS
a(5)-a(14) from Giovanni Resta, May 23 2013
STATUS
approved