A379725 a(n) = A023900(n*A000396(n)).

2, 6, -60, 126, -32760, -262140, -3145716, 2147483646, -4611686018427387900, -2475880078570760549798248440, -1622592768292133633915780102881260, -340282366920938463463374607431768211452

Offset

1,1

Links

Table of n, a(n) for n=1..12.

Formula

Conjecture: a(n) = (-1)^(n+1)*A023900(n)*A023900(A000396(n)).

Mathematica

nn = 12; A023900[n_] := DivisorSum[n, MoebiusMu[#]  # &]; Table[A023900[PerfectNumber[n]*n], {n, 1, nn}]

Crossrefs

Cf. A379724, A000396, A023900, A000668.

Sequence in context: A083787 A347979 A138286 * A355286 A308532 A102290

Adjacent sequences: A379722 A379723 A379724 * A379726 A379727 A379728

Keyword

sign

Author

Mats Granvik, Antti Karttunen, Dec 31 2024

Status

approved