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%I #10 Dec 21 2020 07:33:09
%S 1,2,2,2,2,2,2,4,4,2,4,2,2,2,2,6,4,4,2,4,4,6,4,2,2,8,2,4,4,2,2,12,8,2,
%T 4,2,8,4,4,2,2,2,16,4,8,12,12,4,4,4,2,2,8,2,6,4,8,4,12,8,2,8,2,18,12,
%U 2,12,4,4,2,4,4,8,4,2,10,8,12,6
%N a(n) = A000010(2*n + 1)/A053447(n), for n >= 0.
%C This gives the number of seeds S(2*n+1) = a(n) needed for the complete quadrupling system modulo 2*n + 1 given in A339046.
%F a(n) = phi(2*n + 1)/A053447(n), for n >= 0, with phi = A000010.
%t Array[EulerPhi[#]/MultiplicativeOrder[4, #] &[2 # + 1] &, 61, 0] (* _Michael De Vlieger_, Dec 13 2020 *)
%o (PARI) a(n) = eulerphi(2*n+1)/znorder(Mod(4, 2*n+1)); \\ _Michel Marcus_, Dec 15 2020
%Y Cf. A000010, A053447, A339046.
%K nonn,easy
%O 0,2
%A _Wolfdieter Lang_, Dec 13 2020