A009230 a(n) = lcm(n, d(n)).

1, 2, 6, 12, 10, 12, 14, 8, 9, 20, 22, 12, 26, 28, 60, 80, 34, 18, 38, 60, 84, 44, 46, 24, 75, 52, 108, 84, 58, 120, 62, 96, 132, 68, 140, 36, 74, 76, 156, 40, 82, 168, 86, 132, 90, 92, 94, 240, 147, 150, 204, 156, 106, 216, 220, 56, 228, 116, 118, 60, 122, 124, 126, 448

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Fixed points of this sequence are the refactorable numbers (A033950), i.e. a(A033950(n)) = A033950(n). - Labos Elemer, Nov 18 2002

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..20000 (first 1000 terms from T. D. Noe)

Crossrefs

Cf. A000005, A033950.

Programs

Maple

a:= n-> ilcm(n, numtheory[tau](n)):
seq(a(n), n=1..100);  # Alois P. Heinz, Jan 14 2017

Mathematica

Table[LCM[n,DivisorSigma[0,n]],{n,70}] (* Harvey P. Dale, Jul 31 2016 *)