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a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} gcd(x_1, n)/gcd(x_1, x_2, x_3, n).
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%I #9 May 21 2024 08:47:23

%S 1,11,43,115,221,473,631,1139,1609,2431,2531,4945,4213,6941,9503,

%T 10867,9521,17699,13339,25415,27133,27841,23783,48977,39721,46343,

%U 55555,72565,47909,104533,58591,100979,108833,104731,139451,185035,99901,146729,181159,251719

%N a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} gcd(x_1, n)/gcd(x_1, x_2, x_3, n).

%H Seiichi Manyama, <a href="/A373060/b373060.txt">Table of n, a(n) for n = 1..200</a>

%o (PARI) a(n) = sum(i=1, n, sum(j=1, n, sum(k=1, n, gcd(i, n)/gcd([i, j, k, n]))));

%Y Cf. A372952, A373061.

%K nonn,mult

%O 1,2

%A _Seiichi Manyama_, May 21 2024