A084391 For n>3, a(n) = smallest number divisible by exactly n-2 previous terms; a(n)=n for n<=3.

1, 2, 3, 4, 6, 18, 12, 24, 36, 108, 72, 144, 216, 648, 432, 864, 1296, 3888, 2592, 5184, 7776, 23328, 15552, 31104, 46656, 139968, 93312, 186624, 279936, 839808, 559872, 1119744, 1679616, 5038848, 3359232, 6718464, 10077696, 30233088

Offset

1,2

Comments

Values are 3-smooth (A003586).

Links

Table of n, a(n) for n=1..38.

Formula

G.f. [x * (6x^6-6x^5-4x^3-3x^2-2x-1)]/(1-6x^4) (conjectured). - Ralf Stephan, Feb 03 2004

Crossrefs

Sequence in context: A271360 A236413 A069860 * A259383 A220702 A342503

Adjacent sequences: A084388 A084389 A084390 * A084392 A084393 A084394

Keyword

nonn

Author

Amarnath Murthy, May 30 2003

Extensions

More terms from Reinhard Zumkeller, Jun 02 2003

Status

approved