A353785 a(n) = A353783(n) / A080398(n).

1, 1, 2, 1, 1, 2, 4, 1, 1, 1, 2, 2, 1, 4, 2, 1, 3, 1, 2, 1, 4, 2, 4, 2, 1, 1, 4, 4, 1, 2, 16, 3, 2, 3, 4, 1, 1, 2, 2, 1, 1, 4, 2, 2, 1, 4, 8, 2, 1, 1, 6, 1, 9, 4, 2, 4, 2, 1, 2, 2, 1, 16, 4, 1, 1, 2, 2, 3, 4, 4, 12, 1, 1, 1, 2, 2, 4, 2, 8, 1, 11, 1, 2, 4, 3, 2, 2, 2, 3, 1, 4, 4, 16, 8, 2, 6, 7, 1, 2, 1, 1, 6, 4, 1, 4

Offset

1,3

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Index entries for sequences related to sigma(n)

Formula

a(n) = A353783(n) / A080398(n).

Mathematica

Array[Apply[LCM, DivisorSigma[1, Power @@@ FactorInteger[#]]]/Apply[Times, FactorInteger[DivisorSigma[1, #]][[All, 1]]] &, 105] (* Michael De Vlieger, May 08 2022 *)

Prog

(PARI)
A080398(n) = factorback(factor(sigma(n))[, 1]);
A353783(n) = { my(f=factor(n)~); lcm(vector(#f, i, sigma(f[1, i]^f[2, i]))); };
A353785(n) = (A353783(n) / A080398(n));

Crossrefs

Cf. A000203, A080398, A353783.

Sequence in context: A297159 A293438 A318622 * A245195 A340191 A182105

Adjacent sequences: A353782 A353783 A353784 * A353786 A353787 A353788

Keyword

nonn

Author

Antti Karttunen, May 08 2022

Status

approved