A192217 a(1)=1; a(n) = n*lcm(n, a(n-1)) for n > 1.

1, 4, 36, 144, 3600, 21600, 1058400, 8467200, 76204800, 762048000, 92207808000, 1106493696000, 186997434624000, 2617964084736000, 39269461271040000, 628311380336640000, 181581988917288960000, 3268475800511201280000, 1179919763984543662080000

Offset

1,2

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..200

Formula

a(n) = A000142(n)*A034386(n). - Arkadiusz Wesolowski, Mar 28 2012

Maple

a := proc(n) option remember: if(n=1)then return 1:fi: return n*lcm(n, a(n-1)): end: seq(a(n), n=1..19); # Nathaniel Johnston, Jun 26 2011

Mathematica

a[1]=1; a[n_]:=a[n]=n LCM[n, a[n-1]];
Table[a[n], {n, 1, 20}]

Crossrefs

Sequence in context: A065886 A069053 A193282 * A186434 A270989 A272557

Adjacent sequences: A192214 A192215 A192216 * A192218 A192219 A192220

Keyword

nonn,easy

Author

José María Grau Ribas, Jun 25 2011

Status

approved