OFFSET
1,2
COMMENTS
If k is prime then k is in the sequence if and only if k == 2 or 3 (mod 5).
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000
FORMULA
a(n) seems to be asymptotic to c*n*log(n) where c = 1.5... - Benoit Cloitre, Jan 10 2003
MATHEMATICA
Module[{nn = 500, fib}, fib = Thread[{Range[nn], Fibonacci[Range[nn]]}]; Transpose[Select[fib, Mod[Last[#], First[#]] == First[#] - 1 &]][[1]]] (* Harvey P. Dale, May 21 2014 *)
Select[Range[500], Mod[Fibonacci[#], #] == # - 1 &] (* Alonso del Arte, Nov 20 2018 *)
PROG
(PARI) isok(k) = Mod(fibonacci(k), k) == -1; \\ Michel Marcus, Nov 21 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Name clarified by Alonso del Arte and Michel Marcus, Nov 20 2018
STATUS
approved