A295313 - OEIS

%I #8 Nov 23 2017 12:28:30

%S 1,1,2,1,2,4,4,1,1,6,4,4,2,8,8,1,6,3,4,6,16,12,8,4,1,6,8,8,2,24,16,9,

%T 16,18,16,1,2,4,8,6,6,32,4,12,6,24,16,4,3,3,24,14,18,8,24,8,16,6,4,24,

%U 2,32,8,1,12,48,4,18,32,48,24,3,2,6,4,4,32,24,16,6,11,18,12,32,36,4,8,12,6,18,16,24,64,48,8

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

%H Antti Karttunen, <a href="/A295313/b295313.txt">Table of n, a(n) for n = 1..16384</a>

%F a(n) = A009195(A000203(n)).

%o (PARI) a(n) = my(sn = sigma(n)); gcd(sn, eulerphi(sn)); \\ _Michel Marcus_, Nov 23 2017

%Y Cf. A000010, A000203, A009195, A295311, A295314, A295315.

%K nonn

%O 1,3

%A _Antti Karttunen_, Nov 22 2017