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a(n) = gcd(sigma(n), A276086(n)).
20

%I #14 Mar 10 2024 09:32:18

%S 1,3,2,1,6,1,2,15,1,9,6,1,2,3,6,1,18,1,10,3,2,9,6,5,1,3,10,1,30,1,2,

%T 21,6,9,6,7,2,15,14,45,42,1,2,21,6,9,6,1,1,3,6,7,18,5,2,15,10,45,30,7,

%U 2,3,2,1,42,1,2,21,6,9,18,5,2,3,2,35,6,7,10,3,1,63,42,7,2,3,30,45,90,1,14,21,2,9,6,7,98,3,6,7,6,1,2,105,6

%N a(n) = gcd(sigma(n), A276086(n)).

%H Antti Karttunen, <a href="/A324644/b324644.txt">Table of n, a(n) for n = 1..30030</a>

%F a(n) = gcd(A000203(n), A276086(n)).

%o (PARI)

%o A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };

%o A324644(n) = gcd(sigma(n),A276086(n));

%Y Cf. A000203, A009194, A276086, A324198, A324534, A324645, A324646, A364286.

%Y Cf. A088828 (positions of even terms), A176693 (of odd terms).

%K nonn

%O 1,2

%A _Antti Karttunen_, Mar 11 2019