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 A138859 Smallest prime factor of Fibonacci(3n)-1, i.e., A020639(A000071(3n)). 1
 7, 3, 11, 3, 3, 5, 199, 13, 13, 3, 37, 3, 3, 89, 5, 11, 7, 3, 59, 3, 3, 11, 11, 37, 37, 3, 370248451, 3, 3, 139, 13, 5, 5, 3, 5, 3, 3, 59, 709, 557, 127, 3, 11, 3, 3, 5, 9375829, 73, 7, 3, 29, 3, 3, 2789, 5, 11, 47, 3, 13, 3, 3, 11, 11, 13, 7, 3, 809, 3, 3, 953, 47927441, 5, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS F(n)-1 is even if n is not a multiple of 3. LINKS Chai Wah Wu, Table of n, a(n) for n = 2..379 FORMULA a(n) = A020639(A000071(3n)). MATHEMATICA Table[FactorInteger[Fibonacci[3n]-1][[1, 1]], {n, 2, 80}] (* Harvey P. Dale, Aug 08 2017 *) PROG (PARI) A138859(n)=factor(fibonacci(3*n)-1)[1, 1] /* A138859 is defined only for n>1 ! */ CROSSREFS Cf. A000071. Sequence in context: A084000 A168197 A257324 * A257328 A076569 A061194 Adjacent sequences:  A138856 A138857 A138858 * A138860 A138861 A138862 KEYWORD nonn AUTHOR M. F. Hasler, Apr 05 2008 STATUS approved

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Last modified December 4 21:58 EST 2020. Contains 338941 sequences. (Running on oeis4.)