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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A018254 Divisors of 28. 11
1, 2, 4, 7, 14, 28 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

28 is the second perfect number A000396(2) and 7 is the second Mersenne prime A000668(2). For the structure of this sequence and its representation in base 2, see A135652. - Omar E. Pol, Mar 03 2008

LINKS

Table of n, a(n) for n=1..6.

Index entries for sequences related to divisors of numbers

FORMULA

a(n) = A161713(n-1). - Reinhard Zumkeller, Jun 21 2009

PROG

(PARI) divisors(28) \\ Charles R Greathouse IV, Jun 21 2017

CROSSREFS

Cf. A000396, A000668, A135652.

Sequence in context: A094057 A119267 A144978 * A218341 A018660 A018692

Adjacent sequences:  A018251 A018252 A018253 * A018255 A018256 A018257

KEYWORD

nonn,fini,full,easy

AUTHOR

N. J. A. Sloane.

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 May 25 23:28 EDT 2020. Contains 334607 sequences. (Running on oeis4.)