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 A324733 #8 Mar 17 2019 21:07:45 %S A324733 0,1,2,3,3,1,4,2,4,4,5,4,6,3,4,1,7,3,8,3,6,5,9,2,5,6,3,6,10,4,11,3,5, %T A324733 7,5,4,12,7,6,1,13,2,14,7,6,9,15,3,6,4,1,8,16,1,7,5,8,8,17,4,18,11,3, %U A324733 4,6,7,19,9,9,4,20,5,21,12,6,10,6,7,22,4,3,13,23,7,6,14,10,5,24,7,8,11,11,15,8,3,25,2,8,6,26,9,27,2,5 %N A324733 a(n) = 0 if A324712(n) = 0, otherwise a(n) = 1 + A000523(A324712(n)) - A007814(A324712(n)). %H A324733 Antti Karttunen, <a href="/A324733/b324733.txt">Table of n, a(n) for n = 1..10000</a> (based on Hans Havermann's factorization of A156552) %H A324733 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A324733 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A324733 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A324733 If A324712(n) = 0, then a(n) = 0, otherwise a(n) = 1 + A324728(n) - A324724(n). %o A324733 (PARI) %o A324733 A324712(n) = { my(v=0); fordiv(n, d, if(issquarefree(n/d), v=bitxor(v, A323243(d)))); (v); }; \\ Needs also code from A323243. %o A324733 A000523(n) = if( n<1, 0, #binary(n) - 1); \\ From A000523 %o A324733 A007814(n) = valuation(n,2) %o A324733 A324733(n) = { my(k=A324712(n)); if(!k,k,1 + (A000523(k)-A007814(k))); }; %Y A324733 Cf. A323243, A324712, A324724, A324728, A324734, A324735. %K A324733 nonn %O A324733 1,3 %A A324733 _Antti Karttunen_, Mar 17 2019