A214707 Least m>0 such that 3^n-m and 4^n-m are relatively prime.

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

Offset

1,4

Links

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

Example

gcd(81-1,256-1) = 5 and gcd(81-2, 256-2) = 1, so a(4) = 2.

Mathematica

Table[m = 1; While[GCD[3^n - m, 4^n - m] != 1, m++]; m, {n, 1, 140}]

Crossrefs

Cf. A214074, A214180.

Sequence in context: A205599 A327891 A265671 * A083039 A106253 A078720

Adjacent sequences: A214704 A214705 A214706 * A214708 A214709 A214710

Keyword

nonn,easy

Author

Clark Kimberling, Jul 27 2012

Status

approved