cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A018254 Divisors of 28.

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%I A018254 #19 Jul 08 2025 06:33:26
%S A018254 1,2,4,7,14,28
%N A018254 Divisors of 28.
%C A018254 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
%H A018254 <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a>
%F A018254 a(n) = A161713(n-1). - _Reinhard Zumkeller_, Jun 21 2009
%t A018254 Divisors[28] (* _Harvey P. Dale_, Jun 08 2022 *)
%o A018254 (PARI) divisors(28) \\ _Charles R Greathouse IV_, Jun 21 2017
%Y A018254 Cf. A000396, A000668, A135652.
%K A018254 nonn,fini,full,easy
%O A018254 1,2
%A A018254 _N. J. A. Sloane_