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 A324868 #5 Mar 18 2019 21:49:54
%S A324868 0,0,0,1,0,1,0,1,2,0,0,1,0,1,1,2,0,1,0,1,1,1,0,1,0,1,2,1,0,1,0,1,0,1,
%T A324868 2,2,0,1,2,1,0,1,0,1,2,1,0,1,0,0,1,1,0,1,2,1,2,1,0,1,0,1,2,3,0,1,0,1,
%U A324868 0,1,0,2,0,1,1,1,1,1,0,1,2,1,0,1,2,1,2,1,0,2,2,1,0,1,1,3,0,0,2,2,0,1,0,1,2
%N A324868 Binary weight of A324398(n).
%H A324868 Antti Karttunen, <a href="/A324868/b324868.txt">Table of n, a(n) for n = 1..10000</a> (based on Hans Havermann's factorization of A156552)
%H A324868 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%H A324868 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%H A324868 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A324868 a(n) = A000120(A324398(n)).
%o A324868 (PARI)
%o A324868 A156552(n) = {my(f = factor(n), p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552
%o A324868 A324398(n) = { my(k=A156552(n)); bitand(k,(A323243(n)-k)); }; \\ Needs also code from A323243.
%o A324868 A324868(n) = hammingweight(A324398(n));
%Y A324868 Cf. A000120, A156552, A323243, A324398, A324816.
%K A324868 nonn
%O A324868 1,9
%A A324868 _Antti Karttunen_, Mar 18 2019