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%I #7 Nov 17 2019 16:06:49
%S 1,3,2,4,3,5,7,5,6,9,6,10,6,8,13,10,9,15,9,12,11,18,10,15,16,14,22,18,
%T 15,18,24,15,25,12,27,18,28,22,18,24,20,25,21,27,18,34,23,30,28,21,37,
%U 24,30,39,26,33,20,39,27,43,30,29,45,30,36,40,27,48
%N phi(A327922(n))/4, for n >= 1, with phi = A000010 (Euler's totient).
%C This sequence applies to the odd m >= 3 numbers collected in A327922 with 4 dividing phi(2*m) = phi(m). The analog for even m is: every even numbers m >= 4 has even phi(2*m)/2 = A062570(m/2) = 2*A055034(m/2), This means that phi(2*m)/4 = A055034(m/2), for every even m >= 4.
%F a(n) = A000010(A327922(n))/4, for n >= 1.
%e n = 1: A327922(1) = 5, A000010(5) = 4, hence a(1) = 1.
%e n = 5: A327922(5) = 21 = 3*7, A000010(21) = 2*6 = 12, hence a(5) = 3.
%t Select[EulerPhi[Range[3, 200, 2]]/4, IntegerQ] (* _Amiram Eldar_, Nov 17 2019 *)
%Y Cf. A000010, A055034, A062570, A327922.
%K nonn,easy
%O 1,2
%A _Wolfdieter Lang_, Nov 17 2019
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