login
A214713
a(n) is the least m > 0 such that Fibonacci(n+1)-m and n-m are relatively prime.
2
2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 3, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 2, 2, 1, 2, 1, 2, 3, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 1, 2, 1, 2
OFFSET
1,1
LINKS
EXAMPLE
gcd(21-1,7-1) = 2 and gcd(21-2,7-2) = 1, so a(7) = 2.
MATHEMATICA
Table[m = 1; While[GCD[Fibonacci[n+1] - m, n - m] != 1, m++]; m, {n, 1, 140}]
CROSSREFS
Cf. A214712.
Sequence in context: A131718 A131017 A244227 * A049046 A227945 A003647
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jul 27 2012
STATUS
approved