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 A090206 Nonprime Fibonacci numbers. 10
 0, 1, 1, 8, 21, 34, 55, 144, 377, 610, 987, 2584, 4181, 6765, 10946, 17711, 46368, 75025, 121393, 196418, 317811, 832040, 1346269, 2178309, 3524578, 5702887, 9227465, 14930352, 24157817, 39088169 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS It is possible to find a run of at least length n (not necessarily exactly n) such that n consecutive terms in this sequence are also consecutive in the sequence of Fibonacci numbers. However, it is not possible for such a run to be of exactly length n if n is even. - Alonso del Arte, Nov 23 2010 Some terms of this sequence have prime indices in the sequence of Fibonacci numbers (A000045), see A050937. - Alonso del Arte, Aug 16 2013 LINKS Table of n, a(n) for n=1..30. EXAMPLE 34 is in the sequence as it is a Fibonacci number and it is composite, the product of 2 and 17. 55 is in the sequence as it is a Fibonacci number and it is composite, the product of 5 and 11. 89 is not in the sequence because, although it is a Fibonacci number, it is prime. MATHEMATICA Select[Fibonacci[Range[0, 50]], !PrimeQ[#] &] (* Vladimir Joseph Stephan Orlovsky, Jul 22 2008 *) CROSSREFS Cf. A000045, A005478, A050937, A182602. Sequence in context: A003249 A134862 A302253 * A139590 A154894 A241986 Adjacent sequences: A090203 A090204 A090205 * A090207 A090208 A090209 KEYWORD easy,nonn AUTHOR Felix Tubiana, Jan 22 2004 STATUS approved

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Last modified October 1 18:15 EDT 2023. Contains 365828 sequences. (Running on oeis4.)