A214713 a(n) is the least m > 0 such that Fibonacci(n+1)-m and n-m are relatively prime.

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

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

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

Adjacent sequences: A214710 A214711 A214712 * A214714 A214715 A214716

Keyword

nonn,easy

Author

Clark Kimberling, Jul 27 2012

Status

approved