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 A378644 #7 Dec 03 2024 19:49:59
%S A378644 1,0,1,0,3,-2,5,0,3,-2,9,0,11,-2,1,0,15,-2,17,-2,3,-2,21,0,15,-2,9,-4,
%T A378644 27,-2,29,0,7,-2,13,0,35,-2,9,0,39,-6,41,-4,3,-2,45,0,35,-10,13,-4,51,
%U A378644 -10,25,0,15,-2,57,2,59,-2,9,0,31,-14,65,-4,19,-18,69,0,71,-2,5,-4,43,-18,77,0,27,-2,81,4,43
%N A378644 Möbius transform of A103977.
%H A378644 Antti Karttunen, <a href="/A378644/b378644.txt">Table of n, a(n) for n = 1..20000</a>
%F A378644 a(n) = Sum_{d|n} A008683(d)*A103977(n/d).
%F A378644 a(n) = A083254(n) if n is a non-abundant number (A263837), and apparently never on abundant n, A005101.
%o A378644 (PARI) A378644(n) = sumdiv(n,d,moebius(n/d)*A103977(d));
%Y A378644 Cf. A005101, A008683, A083254, A263837, A103977.
%K A378644 sign
%O A378644 1,5
%A A378644 _Antti Karttunen_, Dec 03 2024