A191836 The slowest growing sequence that satisfies: a(1) = 1, a(n) is a multiple of n and a(n-1), and a(n) > a(n-1).

1, 2, 6, 12, 60, 120, 840, 1680, 5040, 10080, 110880, 221760, 2882880, 5765760, 11531520, 23063040, 392071680, 784143360, 14898723840, 29797447680, 59594895360, 119189790720, 2741365186560, 5482730373120, 27413651865600

Offset

1,2

Comments

a(n)=A072486(n) for n<15

Links

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

Formula

a(1) = 1; for n > 1, a(n) = a(n-1) * (if n is a prime power p^k then p else 2). - Franklin T. Adams-Watters, Jan 13 2012

Mathematica

a[1]=1; a[n_]:=a[n]=If[LCM[n, a[n-1]]==a[n-1], 2 *a[n-1], LCM[n, a[n-1]]]

Crossrefs

Sequence in context: A309233 A135060 A185021 * A072486 A096123 A081125

Adjacent sequences: A191833 A191834 A191835 * A191837 A191838 A191839

Keyword

nonn

Author

José María Grau Ribas, Jun 17 2011

Status

approved