A009242 a(n) = lcm(n, sigma(n)).

1, 6, 12, 28, 30, 12, 56, 120, 117, 90, 132, 84, 182, 168, 120, 496, 306, 234, 380, 420, 672, 396, 552, 120, 775, 546, 1080, 56, 870, 360, 992, 2016, 528, 918, 1680, 3276, 1406, 1140, 2184, 360, 1722, 672, 1892, 924, 1170, 1656, 2256, 1488, 2793, 4650, 1224, 2548

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• easy

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A009194, A017665, A064987.

Programs

Mathematica

A009242[n_]:=LCM[DivisorSigma[1,n],n]; Array[A009242,100] (* Enrique Pérez Herrero, Aug 25 2011 *)

PARI

a(n) = lcm(n, sigma(n)); \\ Amiram Eldar, Mar 27 2024

Formula

a(n) = n*A017665(n). - Enrique Pérez Herrero, Aug 25 2011

a(n) = A064987(n)/A009194(n). - Amiram Eldar, Mar 27 2024