A018254 Divisors of 28.

1, 2, 4, 7, 14, 28

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• fini
• full
• easy

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

• Index entries for sequences related to divisors of numbers

Crossrefs

Cf. A000396, A000668, A135652.

Programs

Mathematica

Divisors[28] (* Harvey P. Dale, Jun 08 2022 *)

PARI

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

Formula

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