A214062 - OEIS

%I #8 Jul 27 2012 18:01:15

%S 1,3,5,1,9,11,1,15,2,1,21,23,1,2,29,1,33,35,1,39,41,1,3,2,1,51,53,1,2,

%T 3,1,63,65,1,69,5,1,75,2,1,81,83,1,2,89,1,5,95,1,99,3,1,105,2,1,111,

%U 113,1,2,119,1,6,125,1,3,131,1,135,2,1,141,3,1,2,6,1,153,155,1

%N Least m>0 such that gcd(2*n+m, 2*n-1-m) > 1.

%H Clark Kimberling, <a href="/A214062/b214062.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A214061(n)-1 for n>=1.

%e gcd(4+1, 3-1) = gcd(4+2, 3-2) = 1 and gcd(4+3, 3-3) > 1, so that a(2) = 3.

%t b[n_] := 2 n; c[n_] := 2 n-1;

%t Table[m = 1; While[GCD[b[n] + m, c[n] - m] == 1, m++]; m, {n, 1, 150}]

%Y Cf. A214061.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Jul 25 2012