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a(n) = gcd(A034448(n)-n, n-A048146(n)), where A034448 and A048146 are respectively the sum of unitary and non-unitary divisors of n.
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%I #9 May 28 2019 19:35:12

%S 1,1,1,1,1,6,1,1,1,2,1,4,1,2,3,1,1,3,1,2,1,2,1,12,1,2,1,12,1,6,1,1,3,

%T 2,1,1,1,2,1,2,1,6,1,4,3,2,1,4,1,7,3,6,1,6,1,8,1,2,1,12,1,2,1,1,1,6,1,

%U 2,3,2,1,3,1,2,1,12,1,6,1,2,1,2,1,4,1,2,3,4,1,18,7,4,1,2,5,12,1,1,21,1,1,6,1,2,3

%N a(n) = gcd(A034448(n)-n, n-A048146(n)), where A034448 and A048146 are respectively the sum of unitary and non-unitary divisors of n.

%H Antti Karttunen, <a href="/A325813/b325813.txt">Table of n, a(n) for n = 1..65537</a>

%F a(n) = gcd(A034460(n), A325814(n)).

%o (PARI)

%o A034448(n) = { my(f=factorint(n)); prod(k=1, #f~, 1+(f[k, 1]^f[k, 2])); }; \\ After code in A034448

%o A034460(n) = (A034448(n) - n);

%o A048146(n) = (sigma(n)-A034448(n));

%o A325814(n) = (n-A048146(n));

%o A325813(n) = gcd(A034460(n), A325814(n));

%Y Cf. A034460, A323166, A325812, A325814.

%Y Cf. also A325385.

%K nonn

%O 1,6

%A _Antti Karttunen_, May 23 2019