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 A138473 a(n) = Fibonacci(8*n). 2
 0, 21, 987, 46368, 2178309, 102334155, 4807526976, 225851433717, 10610209857723, 498454011879264, 23416728348467685, 1100087778366101931, 51680708854858323072, 2427893228399975082453, 114059301025943970552219, 5358359254990966640871840 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Colin Barker, Table of n, a(n) for n = 0..500 Index entries for linear recurrences with constant coefficients, signature (47,-1). FORMULA a(n) = Fibonacci(4*n)*Lucas(4*n) = 21*A049668(n). G.f.: 21*x / ( 1-47*x+x^2 ). - R. J. Mathar, Sep 30 2013 From Colin Barker, Apr 06 2017: (Start) a(n) = (47 + 21*sqrt(5))^(1-n)*(-2^n+(2207 + 987*sqrt(5))^n) / (105 + 47*sqrt(5)). a(n) = 47*a(n-1) - a(n-2) for n > 1. (End) MATHEMATICA Fibonacci[8Range[0, 20]] (* Harvey P. Dale, Jun 22 2013 *) PROG (MuPAD) numlib::fibonacci(8*n) \$ n = 0..25; (Sage) [fibonacci(8*n) for n in xrange(0, 15)] # Zerinvary Lajos, May 15 2009 (MAGMA) [Fibonacci(8*n): n in [0..100]]; // Vincenzo Librandi, Apr 17 2011 (PARI) concat(0, Vec(21*x / (1 - 47*x + x^2) + O(x^30))) \\ Colin Barker, Apr 06 2017 CROSSREFS Cf. A000032, A000045, A049668, A134498. Sequence in context: A220384 A184133 A004704 * A273281 A186392 A263994 Adjacent sequences:  A138470 A138471 A138472 * A138474 A138475 A138476 KEYWORD nonn,easy AUTHOR Zerinvary Lajos, May 09 2008 STATUS approved

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Last modified October 19 16:00 EDT 2018. Contains 316365 sequences. (Running on oeis4.)