login
Number of ordered triples of integers from [ 2,n ] with no global factor.
1

%I #11 Jul 13 2013 12:01:49

%S 0,2,5,14,21,41,59,89,117,171,209,286,347,432,516,651,744,914,1042,

%T 1219,1382,1634,1806,2091,2323,2629,2895,3300,3562,4026,4386,4843,

%U 5249,5802,6204,6869,7380,8025,8569,9388,9928,10830,11516,12347,13104

%N Number of ordered triples of integers from [ 2,n ] with no global factor.

%H Reinhard Zumkeller, <a href="/A015633/b015633.txt">Table of n, a(n) for n = 2..250</a>

%o (Haskell)

%o a015633 n = length [(x,y,z) | x <- [2..n], y <- [x..n], z <- [y..n],

%o gcd (gcd x y) z == 1]

%o -- _Reinhard Zumkeller_, Nov 28 2011

%K nonn

%O 2,2

%A _Olivier GĂ©rard_