A191778 a(1) = 1; a(n)= 2*lcm(n, a(n - 1)).

1, 4, 24, 48, 480, 960, 13440, 26880, 161280, 322560, 7096320, 14192640, 369008640, 738017280, 1476034560, 2952069120, 100370350080, 200740700160, 7628146606080, 15256293212160, 30512586424320, 61025172848640, 2807157951037440, 5614315902074880, 56143159020748800

Offset

1,2

Comments

n and a(n-1) divide a(n).

Links

Table of n, a(n) for n=1..25.

Mathematica

a[1] = 1; a[n_] := a[n]=2 LCM (n, a[n - 1]); Table[a[n], {n, 100}]
RecurrenceTable[{a[1]==1, a[n]==2*LCM[n, a[n-1]]}, a, {n, 30}] (* Harvey P. Dale, Dec 10 2013 *)

Crossrefs

Sequence in context: A226575 A052645 A353250 * A157625 A128205 A085250

Adjacent sequences: A191775 A191776 A191777 * A191779 A191780 A191781

Keyword

nonn

Author

José María Grau Ribas, Jun 16 2011

Status

approved