A323169 - OEIS

%I #11 Jan 18 2019 20:54:06

%S 1,1,0,1,0,1,0,1,0,11,0,1,0,0,0,1,0,1,0,1,0,23,0,1,0,0,0,29,0,31,0,1,

%T 0,0,0,1,0,0,0,1,0,1,0,23,0,47,0,1,0,0,0,53,0,81,0,29,0,59,0,1,0,0,0,

%U 1,0,67,0,0,0,71,0,1,0,0,0,0,0,79,0,1,0,83,0,1,0,0,0,1,0,0,0,47,0,0,0,1,0,0,0,1,0,103,0,53,0

%N Greatest common divisor of the set of solutions to phi(x) = n, or 0 if n is not a totient.

%H Antti Karttunen, <a href="/A323169/b323169.txt">Table of n, a(n) for n = 1..16384</a>

%H Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI scripts for various problems</a>

%F a(n) = 0 iff A014197(n) == 0.

%o (PARI) A323169(n) = gcd(invphi(n)); \\ With invphi from _Max Alekseyev_'s PARI-script collection

%Y Cf. A000010, A014197, A303745 (positions of terms larger than one), A323514 (their characteristic function).

%K nonn

%O 1,10

%A _Antti Karttunen_, Jan 18 2019