A339813 - OEIS

%I #5 Dec 19 2020 07:59:40

%S 0,1,0,2,0,1,0,1,0,2,0,1,0,3,0,1,0,5,0,1,0,2,0,2,0,1,0,7,0,1,0,2,0,1,

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

%U 0,1,0,1,0,2,0,1,0,3,0,1,0,4,0,1,0,2,0,2,0,1,0,4,0,1,0,2,0,1,0,4,0,1,0,1,0

%N The exponent of the highest power of 2 dividing (A019565(n) - 1).

%C The 2-adic valuation of A339809(n).

%H Antti Karttunen, <a href="/A339813/b339813.txt">Table of n, a(n) for n = 1..65537</a>

%F a(n) = A007814(A339809(n)).

%o (PARI)

%o A019565(n) = { my(m=1, p=1); while(n>0, p = nextprime(1+p); if(n%2, m *= p); n >>= 1); (m); };

%o A339813(n) = valuation((A019565(n)-1),2);

%Y Cf. A007814, A339809, A339814 (bisection).

%K nonn

%O 1,4

%A _Antti Karttunen_, Dec 18 2020