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.
%I A138814 #13 Jul 22 2024 11:44:58 %S A138814 1,2,4,8,16,32,127,254,508,1016,2032,4064 %N A138814 Divisors of 4064 (half the 4th perfect number). %C A138814 The n-th perfect number divided by 2 (A133028(n)) has 2*A090748(n) divisors, then this sequence has 12 members. First 6 members are the first 6 powers of 2 A000079. Last 6 members are multiples of 4th Mersenne prime A000668(4)=127. a(n) written in base 2 has n digit. See A138824 for the structure of this sequence. %H A138814 <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a> %t A138814 Divisors[4064] (* _Paolo Xausa_, Jul 22 2024 *) %o A138814 (PARI) divisors(4064) \\ _Charles R Greathouse IV_, Jun 21 2017 %Y A138814 Perfect number divided by 2: A133028. %Y A138814 Cf. A000043, A000079, A000396, A000668, A090748, A134708, A135654, A138824. %K A138814 easy,fini,full,nonn %O A138814 1,2 %A A138814 _Omar E. Pol_, Mar 31 2008