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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A240845 Numbers n equal to the product of all of their integral proper roots (defined as numbers k in the range 1 < k < n such that k^j = n for some j). 0
64, 729, 15625, 46656, 117649, 1000000, 1771561, 2985984, 4826809, 7529536, 11390625, 24137569, 34012224, 47045881, 64000000, 85766121, 113379904, 148035889, 191102976, 268435456 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers of the form a^b where a is a number that is not a perfect power and b is a perfect number (equal to the sum of its divisors). In other words, A007916^A000396.

LINKS

Table of n, a(n) for n=1..20.

EXAMPLE

64 qualifies because its roots are 2, 4, and 8 and 2*4*8=64.

CROSSREFS

Cf. A007916, A000396.

Sequence in context: A001014 A050753 A074154 * A153160 A113851 A046455

Adjacent sequences:  A240842 A240843 A240844 * A240846 A240847 A240848

KEYWORD

more,nonn

AUTHOR

J. Lowell, Apr 13 2014

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 20 13:13 EST 2018. Contains 317402 sequences. (Running on oeis4.)