OFFSET
1,1
COMMENTS
The number of terms not exceeding 10^m, for m = 1, 2, ..., are 1, 8, 79, 793, 7935, 79349, 793524, 7935094, 79350930, 793509394, ... . Apparently, the asymptotic density of this sequence exists and equals 0.0793509... . - Amiram Eldar, Jun 14 2022
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Range[700], GCD[#, 2^#-1]==3&] (* Harvey P. Dale, Nov 22 2011 *)
Select[Range[700], GCD[#, PowerMod[2, #, #] - 1] == 3 &] (* Amiram Eldar, Jun 14 2022 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Apr 09 2002
STATUS
approved