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Search: id:A003487
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| A003487 |
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a(n) = a(n-1)^2 - 2.
(Formerly M3926)
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+0
4
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| 5, 23, 527, 277727, 77132286527, 5949389624883225721727, 35395236908668169265765137996816180039862527
(list; graph; listen)
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OFFSET
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0,1
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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FORMULA
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a(n)=ceiling(c^(2^n)) where c=(5+sqrt(21))/20 is the largest root of x^2-5x+1=0. - Benoit Cloitre, Dec 03, 2002
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CROSSREFS
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Cf. A001566 (starting with 3), A003010 (starting with 4), A003423 (starting with 6)
Sequence in context: A023275 A018899 A080990 this_sequence A055490 A002811 A120660
Adjacent sequences: A003484 A003485 A003486 this_sequence A003488 A003489 A003490
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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