%I #18 Feb 26 2020 03:34:06
%S 10,6,6,4,4,7,3,4,3,7,4,4,0,6,5,1,4,3,7,4,7,2,3,3,2,2,6,5,2,2,0,6,4,3,
%T 5,4,5,3,1,3,3,4,4,6,2,3,1,6,1,6,3,6,1,4,4,4,1,1,3,6,3,2,4,4,1,1,2,4,
%U 6,0,3,4,3,5,4,1,2,8,2,5,6,2,2,5,1,4,2,4,7,2,1,2,6,1,3,5,2,3,5,3
%N Number of numbers for which the count of nonprimes (i.e., 1 and composites) in their reduced residue set equals n.
%H Giovanni Resta, <a href="/A076366/b076366.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = Card{x; A048864(x) = n}; a(n)=0 if supposedly no such number exists (see A072023).
%e A048864(x) = 13: S = {}, a(13) = 0;
%e A048864(x) = 16: S = {144}, a(16) = 1;
%e A048864(x) = 22: S = {57,92}, a(22) = 2;
%e A048864(x) = 7: S = {13,34,50}, a(7) = 3;
%e A048864(x) = 4: S = {15,22,54,84}, a(4) = 4;
%e A048864(x) = 15: S = {35,64,68,156,240}, a(15) = 5;
%e A048864(x) = 2: S = {5,10,14,20,42,60}, a(2) = 6;
%e A048864(x) = 6: S = {11,21,32,40,72,78,210}, a(6) = 7;
%e A048864(x) = 78: S = {133,177,268,440,490,552,870,990}, a(78) = 8;
%e A048864(x) = 1: S = {1,2,3,4,6,8,12,18,24,30}, a(1) = 10; See A048597.
%o (PARI) listn(nn) = {my(v = vector(10^5, n, eulerphi(n) - (primepi(n) - omega(n)))); vector(nn, k, if (#(w=Vec(select(x->(x==k), v, 1))) == 0, 0, #w));} \\ _Michel Marcus_, Feb 23 2020
%Y Cf. A000010, A000720, A001221, A048597, A048864, A048865, A070971, A072022, A072023, A074915.
%K nonn
%O 1,1
%A _Labos Elemer_, Oct 10 2002