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A133024
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Divisors of 8128, the 4th perfect number.
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5
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1, 2, 4, 8, 16, 32, 64, 127, 254, 508, 1016, 2032, 4064, 8128
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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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.
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LINKS
| Index entries for sequences related to divisors of numbers
O. E. Pol, Determinacion geometrica de los numeros primos y perfectos.
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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).
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CROSSREFS
| Cf. A018254, A018487. Perfect numbers: A000396.
Cf. A000079, A000668, A061645, A133033, A135654.
Sequence in context: A066178 A122189 A194630 * A060376 A047869 A016025
Adjacent sequences: A133021 A133022 A133023 * A133025 A133026 A133027
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KEYWORD
| fini,full,nonn,easy
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Oct 26 2007, Mar 03 2008, Dec 27 2008
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