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 A103609 Fibonacci numbers repeated (cf. A000045). 22
 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 5, 5, 8, 8, 13, 13, 21, 21, 34, 34, 55, 55, 89, 89, 144, 144, 233, 233, 377, 377, 610, 610, 987, 987, 1597, 1597, 2584, 2584, 4181, 4181, 6765, 6765, 10946, 10946, 17711, 17711, 28657, 28657, 46368, 46368, 75025, 75025, 121393 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,7 COMMENTS The usual policy in the OEIS is not to include such "doubled" sequences. This is an exception. - N. J. A. Sloane The Gi2 sums, see A180662, of triangle A065941 equal the terms of this sequence without the two leading zeros. - Johannes W. Meijer, Aug 16 2011 LINKS G. C. Greubel, Table of n, a(n) for n = 0..1000 N. J. A. Sloane, 2178 And All That, Fib. Quart., 52 (2014), 99-120. I. Wloch, U. Bednarz, D. BrĂ³d, A Wloch and M. Wolowiec-Musial, On a new type of distance Fibonacci numbers, Discrete Applied Math., Volume 161, Issues 16-17, November 2013, Pages 2695-2701. Index entries for linear recurrences with constant coefficients, signature (0, 1, 0, 1). FORMULA a(n) = a(n-2) + a(n-4). G.f.: x^2*(1+x)/(1-x^2-x^4). - R. J. Mathar, Sep 27 2008 a(n) = A000045(floor(n/2)). - Johannes W. Meijer, Aug 16 2011 MAPLE A103609 := proc(n): combinat[fibonacci](floor(n/2)) ; end proc: seq(A103609(n), n=0..52); # Johannes W. Meijer, Aug 16 2011 MATHEMATICA a[0] = 0; a[1] = 0; a[2] = 1; a[3] = 1; a[n_Integer?Positive] := a[n] = a[n - 2] + a[n - 4]; aa = Table[a[n], {n, 0, 200}] Join[{0, 0}, LinearRecurrence[{0, 1, 0, 1}, {1, 1, 1, 1}, 60]] (* Vincenzo Librandi, Jan 19 2016 *) PROG (PARI) a(n)=fibonacci(n\2) \\ Charles R Greathouse IV, Oct 07 2015 (PARI) x='x+O('x^50); Vec(x^2*(1+x)/(1-x^2-x^4)) \\ G. C. Greubel, May 01 2017 CROSSREFS Partial sums: A094707. - R. J. Mathar, Sep 27 2008 Cf. A214927. Sequence in context: A090492 A325768 A239949 * A237800 A232697 A129526 Adjacent sequences:  A103606 A103607 A103608 * A103610 A103611 A103612 KEYWORD nonn,easy AUTHOR Roger L. Bagula, Mar 24 2005 EXTENSIONS Edited by N. J. A. Sloane, Dec 01 2006 Incorrect formula deleted by Johannes W. Meijer, Aug 16 2011 STATUS approved

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Last modified August 4 15:50 EDT 2020. Contains 336202 sequences. (Running on oeis4.)