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A069104
Numbers m such that m divides Fibonacci(m+1).
7
1, 2, 3, 7, 13, 17, 23, 37, 43, 47, 53, 67, 73, 83, 97, 103, 107, 113, 127, 137, 157, 163, 167, 173, 193, 197, 223, 227, 233, 257, 263, 277, 283, 293, 307, 313, 317, 323, 337, 347, 353, 367, 373, 377, 383, 397, 433, 443, 457, 463, 467, 487, 503, 523, 547, 557
OFFSET
1,2
COMMENTS
Equals A003631 union A069107.
Let u(1)=u(2)=1 and (m+2)*u(m+2) = (m+1)*u(m+1) + m*u(m); then sequence gives values of k such that u(k) is an integer.
LINKS
MATHEMATICA
Select[Range[6! ], IntegerQ[Fibonacci[ #+1]/# ]&] (* Vladimir Joseph Stephan Orlovsky, Apr 03 2009 *)
PROG
(Haskell)
import Data.List (elemIndices)
a069104 n = a069104_list !! (n-1)
a069104_list =
map (+ 1) $ elemIndices 0 $ zipWith mod (drop 2 a000045_list) [1..]
-- Reinhard Zumkeller, Oct 13 2011
(PARI) is(n)=((Mod([1, 1; 1, 0], n))^n)[1, 1]==0 \\ Charles R Greathouse IV, Feb 03 2014
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Apr 06 2002
STATUS
approved