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a(n) = gcd(n-A326039(n), A326040(n)-n).
15

%I #12 Dec 15 2024 16:29:22

%S 1,1,1,1,4,2,3,1,1,1,1,4,12,2,1,1,8,1,3,1,5,2,1,4,1,5,1,24,28,6,15,1,

%T 1,1,1,1,36,2,1,1,40,2,3,4,4,10,1,4,1,7,15,3,4,2,19,4,1,1,1,8,60,2,1,

%U 1,1,6,3,1,1,2,35,1,72,1,1,12,1,2,3,1,1,1,1,4,1,2,1,4,8,27,5,8,29,2,7,60,48,1,1,1,100,6,3,1,1

%N a(n) = gcd(n-A326039(n), A326040(n)-n).

%H Antti Karttunen, <a href="/A326046/b326046.txt">Table of n, a(n) for n = 1..20000</a>

%F a(n) = gcd(A326044(n), A326045(n)) = gcd(n-A326039(n), A326040(n)-n).

%o (PARI)

%o A008833(n) = (n/core(n));

%o A326039(n) = A008833(sigma(n));

%o A326040(n) = (sigma(n)-A008833(sigma(n)));

%o A326046(n) = gcd(n-A326039(n), A326040(n)-n);

%Y Cf. A000203, A008833, A326039, A326040, A326044, A326045.

%Y Cf. also A009194, A325385, A325813, A325975, A326047, A326048, A326056, A326057, A326060, A326062, A326129, A326130, A326140, A326144.

%K nonn

%O 1,5

%A _Antti Karttunen_, Jun 06 2019