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 A358077 #15 Jan 22 2025 15:41:39
%S A358077 1,1,1,4,1,7,1,12,9,11,1,22,1,15,16,24,1,33,1,34,22,23,1,48,25,27,36,
%T A358077 46,1,62,1,48,34,35,36,72,1,39,40,72,1,84,1,70,69,47,1,96,49,85,52,82,
%U A358077 1,108,56,96,58,59,1,142,1,63,93,96,66,128,1,106,70,130,1,144,1,75
%N A358077 Sum of the nonprime divisors of n whose divisor complement is squarefree.
%H A358077 Antti Karttunen, <a href="/A358077/b358077.txt">Table of n, a(n) for n = 1..20000</a>
%F A358077 a(n) = Sum_{d|n, nonprime d, n/d squarefree} d.
%e A358077 a(8) = 12. The nonprime divisors of 8 whose divisor complements are squarefree are 4 and 8 and their sum is 12.
%t A358077 a[n_] := DivisorSum[n, # &, ! PrimeQ[#] && SquareFreeQ[n/#] &]; Array[a, 100] (* _Amiram Eldar_, Oct 30 2022 *)
%o A358077 (PARI) a(n) = sumdiv(n, d, if (!isprime(d) && issquarefree(n/d), d)); \\ _Michel Marcus_, Oct 30 2022
%Y A358077 Cf. A005117, A284118.
%K A358077 nonn
%O A358077 1,4
%A A358077 _Wesley Ivan Hurt_, Oct 29 2022