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 A378534 #9 Dec 01 2024 13:41:21
%S A378534 1,-1,-1,-2,-1,-2,-1,0,-2,-2,-1,1,-1,-2,-2,0,-1,1,-1,1,-2,-2,-1,2,-2,
%T A378534 -2,0,1,-1,2,-1,0,-2,-2,-2,4,-1,-2,-2,2,-1,2,-1,1,1,-2,-1,0,-2,1,-2,1,
%U A378534 -1,2,-2,2,-2,-2,-1,6,-1,-2,1,0,-2,2,-1,1,-2,2,-1,-1,-1,-2,1,1,-2,2,-1,0,0,-2,-1,6,-2,-2,-2,2,-1,6
%N A378534 Dirichlet convolution of A033879 and A378525.
%C A378534 Möbius transform of A378532.
%H A378534 Antti Karttunen, <a href="/A378534/b378534.txt">Table of n, a(n) for n = 1..20000</a>
%F A378534 a(n) = Sum_{d|n} A033879(d)*A378525(n/d).
%F A378534 a(n) = Sum_{d|n} A008683(d)*A378532(n/d).
%o A378534 (PARI)
%o A378534 A033879(n) = (n+n-sigma(n));
%o A378534 A378542(n) = sumdiv(n,d,d*!(bigomega(n/d)%2));
%o A378534 memoA378525 = Map();
%o A378534 A378525(n) = if(1==n,1,my(v); if(mapisdefined(memoA378525,n,&v), v, v = -sumdiv(n,d,if(d<n,A378542(n/d)*A378525(d),0)); mapput(memoA378525,n,v); (v)));
%o A378534 A378534(n) = sumdiv(n,d,A033879(d)*A378525(n/d));
%Y A378534 Cf. A008683, A033879, A323910, A378532 (inverse Möbius transform), A378533 (Dirichlet inverse), A378542.
%Y A378534 Cf. also A378224.
%K A378534 sign
%O A378534 1,4
%A A378534 _Antti Karttunen_, Dec 01 2024