This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A339814 #7 Dec 19 2020 07:59:50
%S A339814 1,2,1,1,2,1,3,1,5,1,2,2,1,7,1,2,1,6,1,1,4,1,2,1,2,1,5,3,1,2,1,4,1,2,
%T A339814 1,1,2,1,3,1,4,1,2,2,1,4,1,2,1,4,1,1,5,1,2,1,2,1,4,3,1,2,1,1,3,1,2,2,
%U A339814 1,3,1,4,1,2,1,1,2,1,3,1,2,1,3,6,1,2,1,2,1,4,1,1,5,1,2,1,3,1,2,2,1,3,1,5,1
%N A339814 The exponent of the highest power of 2 dividing (A019565(2n) - 1).
%C A339814 The 2-adic valuation of A339809(2n).
%H A339814 Antti Karttunen, <a href="/A339814/b339814.txt">Table of n, a(n) for n = 1..65537</a>
%F A339814 a(n) = A007814(A339809(2*n)) = A007814(A019565(2*n)-1).
%F A339814 a(n) = A007814(A003961(A019565(n))-1).
%o A339814 (PARI)
%o A339814 A019565(n) = { my(m=1, p=1); while(n>0, p = nextprime(1+p); if(n%2, m *= p); n >>= 1); (m); };
%o A339814 A339814(n) = valuation((A019565(2*n)-1),2);
%Y A339814 Bisection of A339813.
%Y A339814 Cf. A003961, A007814, A019565, A339809, A339815, A339822.
%K A339814 nonn
%O A339814 1,2
%A A339814 _Antti Karttunen_, Dec 18 2020