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 A329642 #9 Nov 22 2019 18:54:07 %S A329642 0,1,1,2,1,4,1,6,0,5,1,11,1,16,2,6,1,13,1,19,-3,18,1,24,-4,46,4,23,1, %T A329642 13,1,30,14,82,-2,18,1,256,-12,24,1,39,1,67,9,226,1,52,-12,20,8,131,1, %U A329642 28,-19,72,-12,748,1,53,1,1362,17,22,10,45,1,215,254,43,1,48,1,3838,11,407,-10,109,1,84,-12,5458,1,48,-72,12250,-348,32,1,18 %N A329642 a(n) = Sum_{d|n} [1 == A008683(n/d)] * A323244(d), where A323244(x) gives the deficiency of A156552(x). %H A329642 Antti Karttunen, <a href="/A329642/b329642.txt">Table of n, a(n) for n = 1..10000</a> (based on Hans Havermann's factorization of A156552) %H A329642 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A329642 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A329642 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A329642 a(n) = Sum_{d|n} [1 == A008683(n/d)] * (2*A156552(d) - A323243(d)). %F A329642 a(n) = A329643(n) + A329644(n). %o A329642 (PARI) %o A329642 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 A329642 A323243(n) = if(1==n,0,sigma(A156552(n))); %o A329642 A329642(n) = sumdiv(n,d,(1==moebius(n/d))*((2*A156552(d))-A323243(d))); %Y A329642 Cf. A008683, A156552, A323243, A323244, A329643, A329644. %Y A329642 Cf. A329645 (inverse Möbius transform). %K A329642 sign %O A329642 1,4 %A A329642 _Antti Karttunen_, Nov 21 2019