A131120 a(1)=1. a(n+1) = n!/lcm(a(1),a(2),...,a(n)).

1, 1, 2, 3, 4, 10, 12, 84, 96, 108, 120, 1320, 1440, 18720, 20160, 151200, 483840, 1028160, 1088640, 2298240, 2419200, 50803200, 159667200, 1836172800, 1916006400, 11975040000, 12454041600, 336259123200, 348713164800

Offset

1,3

Links

Harvey P. Dale, Table of n, a(n) for n = 1..897

Example

The LCM of the first 7 terms is 60. So a(8) = 7!/60 = 84.

Maple

A131120 := proc(n) option remember ; if n = 1 then 1; else (n-1)!/lcm(seq(A131120(i), i=1..n-1)) ; fi ; end: seq(A131120(n), n=1..40) ; # R. J. Mathar, Oct 17 2007

Mathematica

nxt[{a_, n_, lst_}]:=Module[{l2=lst, x=(n+1)!/LCM@@lst}, {x, n+1, AppendTo[ l2, x]}]; Transpose[NestList[nxt, {1, 0, {1}}, 30]][[1]] (* Harvey P. Dale, Jun 07 2014 *)

Crossrefs

Cf. A131121.

Sequence in context: A100773 A250112 A193775 * A115195 A095384 A177084

Adjacent sequences: A131117 A131118 A131119 * A131121 A131122 A131123

Keyword

nonn

Author

Leroy Quet, Jun 15 2007

Extensions

More terms from R. J. Mathar, Oct 17 2007

Status

approved