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 A363289 #10 May 26 2023 12:29:07
%S A363289 1,3,4,4,6,12,8,8,9,18,12,16,14,24,24,16,18,27,20,24,32,36,24,32,25,
%T A363289 42,27,32,30,72,32,32,48,54,48,36,38,60,56,48,42,96,44,48,54,72,48,64,
%U A363289 49,75,72,56,54,81,72,64,80,90,60,96,62,96,72,64,84,144,68,72,96,144,72
%N A363289 Sum of the divisor complements of the unitary squarefree divisors of n.
%F A363289 a(n) = n * Sum_{d|n, gcd(d,n/d)=1} mu(d)^2 / d.
%t A363289 a[n_] := DivisorSum[n, n/# &, CoprimeQ[#, n/#] && SquareFreeQ[#] &]; Array[a, 100] (* _Amiram Eldar_, May 26 2023 *)
%o A363289 (PARI) a(n) = sumdiv(n, d, if ((gcd(d, n/d) == 1) && issquarefree(d), n/d)); \\ _Michel Marcus_, May 26 2023
%Y A363289 Cf. A092261.
%K A363289 nonn,easy
%O A363289 1,2
%A A363289 _Wesley Ivan Hurt_, May 26 2023