A214718 Least m>0 such that 5^n-m and n-m are relatively prime.

2, 1, 2, 2, 4, 1, 2, 1, 2, 2, 4, 1, 2, 1, 2, 3, 4, 1, 2, 1, 2, 2, 4, 1, 2, 1, 2, 2, 4, 1, 2, 1, 2, 2, 4, 2, 2, 1, 2, 2, 4, 1, 4, 1, 2, 2, 4, 1, 2, 1, 2, 2, 4, 1, 2, 1, 2, 3, 4, 1, 2, 1, 2, 2, 4, 1, 2, 1, 2, 3, 4, 1, 2, 1, 2, 2, 4, 2, 2, 1, 2, 2, 4, 1, 2, 1, 2

Offset

1,1

Links

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

Example

gcd(5^7-1,6) = 2, gcd(5^7-2,5) = 1, so a(7) = 2.

Mathematica

Table[m = 1; While[GCD[5^n - m, n - m] != 1, m++]; m, {n, 1, 140}]

Crossrefs

Cf. A214716.

Sequence in context: A238212 A255723 A309022 * A367970 A345161 A321319

Adjacent sequences: A214715 A214716 A214717 * A214719 A214720 A214721

Keyword

nonn,easy

Author

Clark Kimberling, Jul 27 2012

Status

approved