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 A378989 #7 Dec 15 2024 09:30:27
%S A378989 1,0,-1,0,-1,0,-2,0,1,0,-2,0,-2,0,1,0,-1,0,-2,0,5,0,-3,0,0,0,-3,0,-3,
%T A378989 0,-4,0,6,0,5,0,-2,0,4,0,-2,0,-3,0,-1,0,-4,0,4,0,1,0,-3,0,3,0,4,0,-4,
%U A378989 0,-4,0,-11,0,6,0,-2,0,8,0,-3,0,-2,0,2,0,9,0,-4,0,6,0,-3,0,1,0,6,0,-3,0,8,0,9,0,2,0,-2,0,-12,0,-3,0,-4,0,-12
%N A378989 Dirichlet inverse of the Möbius transform of binary weight of n.
%H A378989 Antti Karttunen, <a href="/A378989/b378989.txt">Table of n, a(n) for n = 1..65537</a>
%H A378989 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%F A378989 a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d<n} A297115(n/d) * a(d).
%F A378989 a(n) = Sum_{d|n} A378990(d).
%o A378989 (PARI)
%o A378989 A297115(n) = sumdiv(n, d, moebius(n/d)*hammingweight(d));
%o A378989 memoA378989 = Map();
%o A378989 A378989(n) = if(1==n,1,my(v); if(mapisdefined(memoA378989,n,&v), v, v = -sumdiv(n,d,if(d<n,A297115(n/d)*A378989(d),0)); mapput(memoA378989,n,v); (v)));
%Y A378989 Dirichlet inverse of A297115.
%Y A378989 Inverse Möbius transform of A378990.
%Y A378989 Cf. A000120.
%K A378989 sign
%O A378989 1,7
%A A378989 _Antti Karttunen_, Dec 15 2024