login
This site is supported by donations to The OEIS Foundation.

 

Logo

The submissions stack has been unacceptably high for several months now. Please voluntarily restrict your submissions and please help with the editing. (We don't want to have to impose further limits.)

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A072938 Highly composite numbers that are half of the next highly composite number. 12
1, 2, 6, 12, 60, 360, 2520 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A002182(k) such that A002182(k+1) = 2*A002182(k).

Numbers m such that d(m)>=d(k) for 0<k<2m {d(n) being the number of divisors function: A000005(n)}. - Lekraj Beedassy, Dec 16 2004

W. Brefeld (cf. link) gives a proof that there are no other terms. - Klaus Brockhaus, Mar 05 2006

LINKS

Table of n, a(n) for n=1..7.

Werner Brefeld, Ramanujan, zusammengesetzte Zahlen und ihre Teilbarkeit

Achim Flammenkamp Highly Composite Numbers

EXAMPLE

6 = A002182(4) is a term since A002182(5) = 12 = 2*6.

CROSSREFS

Cf. A002182, A002201, A106037, A094348, A003418, A002110.

A165412. - Reinhard Zumkeller, Jan 20 2010

Sequence in context: A189394 A182862 * A160274 A048803 A068625 A162935

Adjacent sequences:  A072935 A072936 A072937 * A072939 A072940 A072941

KEYWORD

nonn,fini,full

AUTHOR

Anon, Aug 12 2002

EXTENSIONS

Edited by Klaus Brockhaus, Aug 13 2002

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified August 28 08:35 EDT 2015. Contains 261118 sequences.