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 A133024 Divisors of 8128, the 4th perfect number. 6
 1, 2, 4, 8, 16, 32, 64, 127, 254, 508, 1016, 2032, 4064, 8128 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS 127 is the 4th Mersenne prime: A000668. The number of divisors of the 4th perfect number is 2*A000043(4)=A061645(4)=14. For the structure of this sequence and its binary expansion, see A135654. LINKS Table of n, a(n) for n=1..14. Index entries for sequences related to divisors of numbers Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos. FORMULA For n=1..7 : a(n) = 2^(n-1). For n=8..14: a(n) = 2^(n-1) - 2^(n-8) = A000668(4)*2^(n-8). MATHEMATICA Divisors[8128] (* Harvey P. Dale, Jul 30 2023 *) PROG (PARI) divisors(8128) \\ Charles R Greathouse IV, Jun 21 2017 CROSSREFS Cf. A018254, A018487. Perfect numbers: A000396. Cf. A000079, A000668, A061645, A133033, A135654. Sequence in context: A251672 A251747 A251761 * A243085 A060376 A047869 Adjacent sequences: A133021 A133022 A133023 * A133025 A133026 A133027 KEYWORD fini,full,nonn,easy AUTHOR Omar E. Pol, Oct 26 2007, Mar 03 2008, Dec 27 2008 STATUS approved

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Last modified December 2 07:23 EST 2023. Contains 367510 sequences. (Running on oeis4.)