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 A369455 #8 Jan 27 2024 16:05:56
%S A369455 0,1,1,-1,1,0,1,1,-1,0,1,-3,1,0,0,-4,1,-6,1,-3,0,0,1,0,-3,0,-5,-3,1,0,
%T A369455 1,1,0,0,0,9,1,0,0,0,1,0,1,-3,-6,0,1,-3,-5,-20,0,-3,1,-8,0,0,0,0,1,0,
%U A369455 1,0,-6,-7,0,0,1,-3,0,0,1,-6,1,0,-20,-3,0,0,1,-3,1,0,1,0,0,0,0,0,1,0,0,-3,0,0,0,0,1,-42,-6,29
%N A369455 Dirichlet convolution of A083345 with A055615 (Dirichlet inverse of n), where A083345(n) = (n'/gcd(n,n')) and n' is the arithmetic derivative of n.
%C A369455 Dirichlet convolution of this sequence with A000010 (Euler phi) is A369068.
%H A369455 Antti Karttunen, <a href="/A369455/b369455.txt">Table of n, a(n) for n = 1..65537</a>
%F A369455 a(n) = Sum_{d|n} A055615(n/d)*A083345(d).
%o A369455 (PARI)
%o A369455 A055615(n) = (n*moebius(n));
%o A369455 A083345(n) = { my(f=factor(n)); numerator(vecsum(vector(#f~, i, f[i, 2]/f[i, 1]))); };
%o A369455 A369455(n) = sumdiv(n, d, A083345(n/d)*A055615(d));
%Y A369455 Cf. A055615, A083345.
%Y A369455 Cf. also A349394, A349396, A369068, A369069.
%K A369455 sign
%O A369455 1,12
%A A369455 _Antti Karttunen_, Jan 27 2024