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 A020749 Pisot sequence T(5,8), a(n) = floor(a(n-1)^2/a(n-2)). 2
 5, 8, 12, 18, 27, 40, 59, 87, 128, 188, 276, 405, 594, 871, 1277, 1872, 2744, 4022, 5895, 8640, 12663, 18559, 27200, 39864, 58424, 85625, 125490, 183915, 269541, 395032, 578948, 848490, 1243523, 1822472, 2670963, 3914487, 5736960, 8407924, 12322412, 18059373 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Colin Barker, Table of n, a(n) for n = 0..1000 FORMULA a(n) = 2*a(n-1) - a(n-2) + a(n-3) - a(n-4) (holds at least up to n = 1000 but is not known to hold in general). Note the warning in A010925 from Pab Ter (pabrlos(AT)yahoo.com), May 23 2004: [A010925] and other examples show that it is essential to reject conjectured generating functions for Pisot sequences until a proof or reference is provided. - N. J. A. Sloane, Jul 26 2016 MATHEMATICA RecurrenceTable[{a[0] == 5, a[1] == 8, a[n] == Floor[a[n - 1]^2/a[n - 2] ]}, a, {n, 0, 40}] (* Bruno Berselli, Feb 05 2016 *) PROG (MAGMA) Txy:=[5, 8]; [n le 2 select Txy[n] else Floor(Self(n-1)^2/Self(n-2)): n in [1..40]]; // Bruno Berselli, Feb 05 2016 (PARI) pisotT(nmax, a1, a2) = {   a=vector(nmax); a[1]=a1; a[2]=a2;   for(n=3, nmax, a[n] = floor(a[n-1]^2/a[n-2]));   a } pisotT(50, 5, 8) \\ Colin Barker, Jul 29 2016 CROSSREFS Subsequence of A020745. See A008776 for definitions of Pisot sequences. Sequence in context: A001043 A118775 A025001 * A120135 A162704 A134650 Adjacent sequences:  A020746 A020747 A020748 * A020750 A020751 A020752 KEYWORD nonn AUTHOR STATUS approved

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Last modified October 23 13:15 EDT 2018. Contains 316528 sequences. (Running on oeis4.)