A214717 - OEIS

%I #6 Jul 30 2012 17:43:18

%S 2,1,1,3,1,3,2,1,1,3,1,1,2,1,2,3,1,1,2,1,1,3,1,1,2,5,1,3,1,1,2,1,1,3,

%T 1,3,2,1,1,3,1,1,2,1,2,3,1,1,2,1,1,3,1,1,2,3,2,3,1,1,2,1,1,3,1,3,2,1,

%U 1,3,1,1,2,1,1,3,1,3,2,1,1,3,1,1,2,3,1

%N Least m>0 such that 4^n-m and n-m are relatively prime.

%H Clark Kimberling, <a href="/A214717/b214717.txt">Table of n, a(n) for n = 1..1000</a>

%e gcd(4^6-1,5) = 5, gcd(4^6-2,4) = 2, gcd(4^6-3,3) = 1, so a(6) = 3.

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

%Y Cf. A214716.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Jul 27 2012