cp's OEIS Frontend

A331176 a(n) = n - n/gcd(n, phi(n)), where phi is Euler totient function.

%I A331176 #9 Aug 20 2020 20:01:16
%S A331176 0,0,0,2,0,3,0,6,6,5,0,9,0,7,0,14,0,15,0,15,14,11,0,21,20,13,24,21,0,
%T A331176 15,0,30,0,17,0,33,0,19,26,35,0,35,0,33,30,23,0,45,42,45,0,39,0,51,44,
%U A331176 49,38,29,0,45,0,31,56,62,0,33,0,51,0,35,0,69,0,37,60,57,0,65,0,75,78,41,0,77,0,43,0,77,0,75
%N A331176 a(n) = n - n/gcd(n, phi(n)), where phi is Euler totient function.
%H A331176 Antti Karttunen, <a href="/A331176/b331176.txt">Table of n, a(n) for n = 1..16384</a>
%H A331176 Antti Karttunen, <a href="/A331176/a331176.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%F A331176 a(n) = n - A109395(n).
%t A331176 Table[n-n/GCD[n,EulerPhi[n]],{n,90}] (* _Harvey P. Dale_, Aug 20 2020 *)
%o A331176 (PARI) A331176(n) = (n - (n/gcd(n, eulerphi(n))));
%Y A331176 Cf. A000010, A009195, A109395.
%Y A331176 Cf. A003277 (indices of zeros).
%K A331176 nonn
%O A331176 1,4
%A A331176 _Antti Karttunen_, Jan 11 2020