login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Divisors of 4064 (half the 4th perfect number).
1

%I #13 Jul 22 2024 11:44:58

%S 1,2,4,8,16,32,127,254,508,1016,2032,4064

%N Divisors of 4064 (half the 4th perfect number).

%C 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 <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a>

%t Divisors[4064] (* _Paolo Xausa_, Jul 22 2024 *)

%o (PARI) divisors(4064) \\ _Charles R Greathouse IV_, Jun 21 2017

%Y Perfect number divided by 2: A133028.

%Y Cf. A000043, A000079, A000396, A000668, A090748, A134708, A135654, A138824.

%K easy,fini,full,nonn

%O 1,2

%A _Omar E. Pol_, Mar 31 2008