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A060901
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Exact power of 3 that divides the n-th Fibonacci number (sequence A000045).
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2
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1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 27, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 27, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1
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OFFSET
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1,4
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LINKS
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FORMULA
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If n is not divisible by 4 then a(n) = 1, if n = 4 * 3^k * m where m is not divisible by 3 then a(n) = 3^(k+1).
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EXAMPLE
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a(12) = 9 because the 12th Fibonacci number is 144 and 144 = 9*16.
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PROG
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(PARI) a(n) = 3^valuation(fibonacci(n), 3) \\Michel Marcus, Jul 30 2013
(Haskell)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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Ahmed Fares (ahmedfares(AT)my-deja.com), May 05 2001
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001
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STATUS
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approved
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