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a(n) = log_2(A094269(n)).
2

%I #17 Sep 25 2024 02:36:31

%S 0,0,1,1,2,1,2,2,2,3,3,4,3,3,3,4,4,4,4,5,4,5,5,5,6,5,5,5,6,6,6,6,6,6,

%T 6,7,7,8,7,7,7,7,7,7,7,8,8,8,8,8,8,9,8,8,8,9,9,9,9,10,9,9,9,9,9,9,10,

%U 10,10,10,10,10,10,10,10,10,11,10,11,11,11,12

%N a(n) = log_2(A094269(n)).

%C A companion sequence of A094269.

%H Amiram Eldar, <a href="/A319821/b319821.txt">Table of n, a(n) for n = 1..10000</a>

%F 2^a(n) = A094269(n) = phi(A003401(n)).

%o (PARI) for(n=1, 1e4, my(i=eulerphi(n)); if(omega(2*i)==1, print1(logint(i,2), ", ")))

%Y Cf. A000010, A003401, A094269.

%K nonn

%O 1,5

%A _Jianing Song_, Sep 28 2018