A214064 a(n) is the least m > 0 such that Fibonacci(n+m) and n-m are not relatively prime.

5, 2, 3, 2, 1, 6, 1, 4, 3, 2, 1, 6, 5, 2, 1, 2, 1, 6, 1, 4, 3, 2, 1, 6, 5, 2, 1, 2, 1, 2, 1, 4, 3, 2, 1, 6, 5, 2, 3, 2, 1, 6, 1, 4, 3, 2, 1, 6, 5, 2, 3, 2, 1, 2, 1, 4, 3, 2, 1, 4, 5, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 5, 2, 1, 2, 1, 6, 1, 4, 3, 2, 1, 6, 5, 2, 1, 2, 1, 5, 1, 4, 3, 2, 1, 6, 5, 2, 3

Offset

1,1

Links

Clark Kimberling, Table of n, a(n) for n = 1..1000

Example

gcd(F(4+1), 4-1) = 1, gcd(F(4+2), 4-2) > 1, so that a(4) = 2.

Mathematica

b[n_] := Fibonacci[n]; c[n_] := n;
Table[m = 1; While[GCD[b[n + m], c[n] - m] == 1, m++]; m, {n, 1, 120}]

Crossrefs

Cf. A214063.

Sequence in context: A178566 A155551 A259027 * A343486 A098584 A081750

Adjacent sequences: A214061 A214062 A214063 * A214065 A214066 A214067

Keyword

nonn,easy

Author

Clark Kimberling, Jul 25 2012

Status

approved