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Search: id:A124105
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| A124105 |
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Practical Fibonacci numbers. |
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+0
1
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| 1, 2, 8, 144, 46368, 832040, 14930352, 267914296, 4807526976
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Melfi proves that this sequence is infinite. The first few practical Fibonacci numbers have indices that are themselves practical (analogous to the property that the prime Fibonacci numbers have prime indices) but Melfi observes that this property is not true in general: F444 is practical although 444 itself is not.
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REFERENCES
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Giuseppe Melfi: "A survey on practical numbers", Rend. Sem. Mat. Univ. Pol. Torino, 53, (1995), 347-359.
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LINKS
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Giuseppe Melfi, A survey on practical numbers
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EXAMPLE
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144 is a member of this sequence because it is the 12th Fibonacci number and is also a practical number.
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CROSSREFS
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Cf. A000045, A005153, A074316.
Sequence in context: A045330 A140050 A009817 this_sequence A079613 A091299 A007314
Adjacent sequences: A124102 A124103 A124104 this_sequence A124106 A124107 A124108
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KEYWORD
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nonn
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AUTHOR
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David Eppstein (eppstein(AT)ics.uci.edu), Dec 13 2006
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