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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A138814 Divisors of 4064 (half the 4th perfect number). 1
 1, 2, 4, 8, 16, 32, 127, 254, 508, 1016, 2032, 4064 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS 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. LINKS PROG (PARI) divisors(4064) \\ Charles R Greathouse IV, Jun 21 2017 CROSSREFS Perfect number divided by 2: A133028. Cf. A000043, A000079, A000396, A000668, A090748, A134708, A135654, A138824. Sequence in context: A078227 A250073 A260873 * A233424 A137181 A272698 Adjacent sequences:  A138811 A138812 A138813 * A138815 A138816 A138817 KEYWORD easy,fini,full,nonn AUTHOR Omar E. Pol, Mar 31 2008 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.

Last modified April 18 19:31 EDT 2021. Contains 343089 sequences. (Running on oeis4.)