login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A160996 a(n) = the smallest positive integer with exactly the same number of divisors as in the first n positive integers combined. 0
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 3 12:41 EST 2021. Contains 349463 sequences. (Running on oeis4.)