OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
a(n) seems to be asymptotic to c*n with c=2.2...
MATHEMATICA
Select[Range[100], !CoprimeQ[2^# - 1, Fibonacci[#]] &] (* Amiram Eldar, Aug 29 2020 *)
PROG
(PARI) isok(n)=gcd(2^n-1, fibonacci(n)) != 1 \\ Edward Jiang, Sep 06 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Sep 07 2002
STATUS
approved