A160996 a(n) = the smallest positive integer with exactly the same number of divisors as in the first n positive integers combined.

1, 4, 16, 24, 48, 192, 120, 240, 4194304, 900, 268435456, 5184, 68719476736, 1099511627776, 3600, 6480, 61440, 805306368, 5040, 46080, 25920, 206158430208, 3932160, 20160, 2415919104, 2985984, 21233664, 1267650600228229401496703205376

Offset

1,2

Comments

a(n) = the smallest positive integer with exactly sum{k=1 to n} d(k) (or sum{k=1 to n} floor(n/k)) divisors.

Links

Table of n, a(n) for n=1..28.

Formula

a(n) = A005179(A006218(n)).

Crossrefs

Cf. A005179, A006218.

Sequence in context: A192199 A145229 A174999 * A337733 A173926 A305884

Adjacent sequences: A160993 A160994 A160995 * A160997 A160998 A160999

Keyword

nonn

Author

Leroy Quet, Jun 01 2009

Extensions

Extended by Ray Chandler, Jun 13 2009

Status

approved