A051548 a(n) = LCM { tau(1), ..., tau(n) }.

1, 1, 2, 2, 6, 6, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 60, 60, 60, 60, 60, 60, 60, 60, 120, 120, 120, 120, 120, 120, 120, 120, 120, 120, 120, 120, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Comments

From Antti Karttunen, Aug 23 2017: (Start)

a(0) = 1 as an empty product.

Records (new values) occur at positions: 0, 2, 4, 6, 24, 36, 64, 120, 840, 900, 1024, 1296, 4096, 7560, ...

(End)

Links

• Antti Karttunen, Table of n, a(n) for n = 0..4096
• Index entries for sequences related to lcm's

Crossrefs

Cf. A000005.

Programs

Maple

a:= proc(n) option remember; `if`(n=0, 1,
       ilcm(a(n-1), numtheory[tau](n)))
    end:
seq(a(n), n=0..55);  # Alois P. Heinz, Dec 11 2024

Mathematica

Block[{nn = 60, s}, s = DivisorSigma[0, Range@ nn]; {1}~Join~Table[LCM @@ s[[1 ;; n]], {n, nn}]] (* Michael De Vlieger, Aug 23 2017 *)

Extensions

a(0) = 1 inserted by Antti Karttunen, Aug 23 2017