cp's OEIS Frontend

A344704 a(n) = gcd(A001615(n)-n, sigma(n)-(A001615(n)+n)).

%I A344704 #8 May 29 2021 20:02:20
%S A344704 1,1,1,1,1,6,1,1,1,2,1,4,1,2,3,1,1,3,1,2,1,2,1,12,1,2,1,20,1,6,1,1,3,
%T A344704 2,1,1,1,2,1,2,1,6,1,4,3,2,1,4,1,1,3,2,1,6,1,8,1,2,1,12,1,2,11,1,1,6,
%U A344704 1,10,3,2,1,3,1,2,1,4,1,6,1,2,1,2,1,4,1,2,3,4,1,18,7,4,1,2,5,12,1,5,3,1,1,6,1,2,3
%N A344704 a(n) = gcd(A001615(n)-n, sigma(n)-(A001615(n)+n)).
%H A344704 Antti Karttunen, <a href="/A344704/b344704.txt">Table of n, a(n) for n = 1..65537</a>
%F A344704 a(n) = gcd(A306927(n), n-A244963(n)) = gcd(A001615(n)-n, sigma(n)-(A001615(n)+n)).
%o A344704 (PARI)
%o A344704 A001615(n) = if(1==n,n, my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1))); \\ After code in A001615
%o A344704 A344704(n) = gcd(A001615(n)-n, sigma(n)-(A001615(n)+n));
%Y A344704 Cf. A000203, A001615, A244963, A306927, A344700, A344705.
%K A344704 nonn
%O A344704 1,6
%A A344704 _Antti Karttunen_, May 28 2021