A123258 a(n) = n-th divisor of the smallest positive integer with at least n divisors.

1, 2, 4, 6, 6, 12, 12, 24, 36, 48, 30, 60, 30, 40, 60, 120, 90, 180, 120, 240, 90, 120, 180, 360, 120, 144, 180, 240, 360, 720, 420, 840, 315, 420, 630, 1260, 420, 560, 840, 1680, 315, 360, 420, 504, 630, 840, 1260, 2520, 360, 420, 504, 560, 630, 720, 840, 1008

Offset

1,2

Comments

a(n) = n-th divisor of A061799(n).

Links

Table of n, a(n) for n=1..56.

Example

The smallest positive integer with at least 11 divisors is 60, which has 12 divisors.
So a(11) = the 11th divisor of 60, which is 30.

Mathematica

f[n_] := Block[{k = 1, d}, While[d = Divisors[k]; Length[d] < n, k++ ]; d[[n]]]; Table[f[n], {n, 60}] (* Ray Chandler, Nov 11 2006 *)
Do[k = 1; While[Length[Divisors[k]] < n, k++ ]; Print[Divisors[k][[n]]], {n, 100}] (* Ryan Propper, Nov 12 2006 *)

Crossrefs

Cf. A061799.

Sequence in context: A141677 A087459 A285103 * A278227 A104968 A286894

Adjacent sequences: A123255 A123256 A123257 * A123259 A123260 A123261

Keyword

nonn

Author

Leroy Quet, Nov 06 2006

Extensions

Extended by Ray Chandler, Nov 11 2006

More terms from Ryan Propper, Nov 12 2006

Status

approved