

A072938


Highly composite numbers that are half of the next highly composite number.


12




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



