A271504 With a(1) = 1, a(n) is the LCM of all 0 < m < n for which a(m) divides n.

1, 1, 2, 6, 2, 60, 2, 210, 2, 630, 2, 13860, 2, 90090, 2, 90090, 2, 3063060, 2, 29099070, 2, 29099070, 2, 1338557220, 2, 3346393050, 2, 10039179150, 2, 582272390700, 2, 9025222055850, 2, 9025222055850, 2, 18050444111700, 2, 333933216066450, 2, 333933216066450

Offset: 1

Author

Peter Kagey, Apr 08 2016

Keywords

• nonn

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..2309 (n = 1..100 from Peter Kagey)

Crossrefs

Cf. A269347, A271503.

Programs

Mathematica

a = {1}; Do[AppendTo[a, LCM @@ Select[Range[n - 1], Divisible[n, a[[#]]] &]], {n, 2, 40}]; a (* Michael De Vlieger, Apr 08 2016 *)

Formula

a(2n + 1) = 2 for all n > 1.

a(n) is even for all n > 2.