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 A379106 #9 Dec 16 2024 22:18:59 %S A379106 1,0,0,0,-2,2,-3,0,-3,2,-7,4,-9,2,2,0,-14,4,-15,4,-1,2,-18,8,-8,2,-4, %T A379106 4,-24,2,-25,0,-2,2,5,12,-33,2,0,8,-37,0,-38,4,10,2,-41,16,-20,0,2,4, %U A379106 -48,2,15,8,0,2,-53,12,-55,2,19,0,16,-8,-63,4,-3,-4,-66,32,-69,2,-2,4,18,-12,-73,16,-15,2,-78,8,30 %N A379106 Dirichlet convolution of A000120 and A323910, where A323910 is the Dirichlet inverse of the deficiency of n, and A000120 is the binary weight of n. %H A379106 Antti Karttunen, <a href="/A379106/b379106.txt">Table of n, a(n) for n = 1..20000</a> %H A379106 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>. %H A379106 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>. %F A379106 a(n) = Sum_{d|n} A000120(d)*A323910(n/d). %o A379106 (PARI) %o A379106 A033879(n) = (n+n-sigma(n)); %o A379106 memoA323910 = Map(); %o A379106 A323910(n) = if(1==n,1,my(v); if(mapisdefined(memoA323910,n,&v), v, v = -sumdiv(n,d,if(d<n,A033879(n/d)*A323910(d),0)); mapput(memoA323910,n,v); (v))); %o A379106 A379106(n) = sumdiv(n,d,hammingweight(d)*A323910(n/d)); %Y A379106 Cf. A000120, A033879, A323910, A379107 (Dirichlet inverse). %Y A379106 Cf. also A294898, A378754, A378756. %K A379106 sign %O A379106 1,5 %A A379106 _Antti Karttunen_, Dec 16 2024