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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A138815 Divisors of 16775168 (half the 5th perfect number). 1
1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 8191, 16382, 32764, 65528, 131056, 262112, 524224, 1048448, 2096896, 4193792, 8387584, 16775168 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The n-th perfect number divided by 2 (A133028(n)) has 2*A090748(n) divisors, then this sequence has 24 members. First 12 members are the first 12 powers of 2 A000079. Last 12 members are multiples of 5th Mersenne prime A000668(5)=8191. a(n) written in base 2 has n digits. See A138825 for the structure of this sequence.

LINKS

Table of n, a(n) for n=1..24.

Index entries for sequences related to divisors of numbers

PROG

(PARI) divisors(16775168) \\ Charles R Greathouse IV, Jun 22 2017

CROSSREFS

Perfect number divided by 2: A133028. Cf. A000043, A000079, A000396, A000668, A090748, A134708, A135655, A138825.

Sequence in context: A260814 A274864 A274863 * A275077 A275065 A180212

Adjacent sequences:  A138812 A138813 A138814 * A138816 A138817 A138818

KEYWORD

easy,fini,full,nonn

AUTHOR

Omar E. Pol, Mar 31 2008

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 November 16 17:04 EST 2019. Contains 329201 sequences. (Running on oeis4.)