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A139044
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Smallest prime divisor of the Fibonacci numbers > 1.
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5
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2, 3, 5, 2, 13, 3, 2, 5, 89, 2, 233, 13, 2, 3, 1597, 2, 37, 3, 2, 89, 28657, 2, 5, 233, 2, 3, 514229, 2, 557, 3, 2, 1597, 5, 2, 73, 37, 2, 3, 2789, 2, 433494437, 3, 2, 139, 2971215073, 2, 13, 5, 2, 3, 953, 2, 5, 3, 2, 59, 353, 2, 4513, 557, 2, 3, 5, 2, 269, 3, 2, 5, 6673, 2
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OFFSET
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1,1
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COMMENTS
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Fibonacci number > 1, divided by its largest proper divisor.
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LINKS
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Amiram Eldar, Table of n, a(n) for n = 1..1406 (terms 1..200 Vincenzo Librandi)
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FORMULA
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a(n) = A000045(n+2)/A032742(A000045(n+2)) = A000045(n+2)/A139045(n).
a(n) = A020639(A000045(n+2)). - Michel Marcus, Nov 15 2014
a(n) = A060383(n+2). - Alois P. Heinz, Oct 11 2015
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MAPLE
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with(numtheory): with(combinat): a:=proc(n) options operator, arrow: op(2, divisors(fibonacci(n))) end proc: seq(a(n), n=3..60); # Emeric Deutsch, May 02 2008
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MATHEMATICA
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First[First[FactorInteger[ # ]]]&/@Fibonacci[Range[3, 40]] (* Harvey P. Dale, Apr 30 2008 *)
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PROG
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(PARI) a(n) = factor(fibonacci(n+2))[1, 1]; \\ Michel Marcus, Nov 15 2014
(MAGMA) [Minimum(PrimeDivisors(Fibonacci(n+2))): n in [1..70]]; // Vincenzo Librandi, Dec 24 2016
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CROSSREFS
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Cf. A000045, A032742, A060383, A133021, A139045.
Sequence in context: A079369 A102867 A060383 * A060442 A060385 A080648
Adjacent sequences: A139041 A139042 A139043 * A139045 A139046 A139047
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KEYWORD
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nonn
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AUTHOR
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Omar E. Pol, Apr 23 2008
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EXTENSIONS
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More terms from Emeric Deutsch and Harvey P. Dale, May 02 2008
More terms from Vincenzo Librandi, Dec 24 2016
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STATUS
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approved
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