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 A379725 #10 Jan 07 2025 08:49:25
%S A379725 2,6,-60,126,-32760,-262140,-3145716,2147483646,-4611686018427387900,
%T A379725 -2475880078570760549798248440,-1622592768292133633915780102881260,
%U A379725 -340282366920938463463374607431768211452
%N A379725 a(n) = A023900(n*A000396(n)).
%F A379725 Conjecture: a(n) = (-1)^(n+1)*A023900(n)*A023900(A000396(n)).
%t A379725 nn = 12; A023900[n_] := DivisorSum[n, MoebiusMu[#] # &]; Table[A023900[PerfectNumber[n]*n], {n, 1, nn}]
%Y A379725 Cf. A379724, A000396, A023900, A000668.
%K A379725 sign
%O A379725 1,1
%A A379725 _Mats Granvik_, _Antti Karttunen_, Dec 31 2024