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The 2-adic valuation of phi(A267099(n)), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes, and phi is Euler totient function.
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%I #7 May 21 2022 08:43:39

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

%T 3,3,1,2,3,3,1,4,2,5,3,2,2,5,2,1,3,2,1,2,5,4,4,1,3,4,1,3,4,5,2,6,3,2,

%U 4,3,5,4,1,1,3,3,6,3,2,4,2,1,2,5,2,2,3,6,1,3,3,3,5,2,3,6,1,2,6,2,1,3,4,3,5

%N The 2-adic valuation of phi(A267099(n)), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes, and phi is Euler totient function.

%H Antti Karttunen, <a href="/A354110/b354110.txt">Table of n, a(n) for n = 1..100000</a>

%F a(n) = A007814(A354102(n)) = A053574(A267099(n)).

%o (PARI)

%o \\ Uses also the program from A267099:

%o A354102(n) = eulerphi(A267099(n));

%o A354110(n) = valuation(A354102(n),2);

%Y Cf. A000010, A007814, A053574, A267099, A354102, A354107.

%K nonn

%O 1,3

%A _Antti Karttunen_, May 20 2022