A138814 - OEIS

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A138814

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

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

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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

Table of n, a(n) for n=1..12.

Index entries for sequences related to divisors of numbers

MATHEMATICA

Divisors[4064] (* Paolo Xausa, Jul 22 2024 *)

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