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A018909
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Define the sequence S(a_0,a_1) by a_{n+2} is the least integer such that a_{n+2}/a_{n+1}>a_{n+1}/a_n for n >= 0. This is S(3,6).
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1
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3, 6, 13, 29, 65, 146, 328, 737, 1657, 3726, 8379, 18843, 42375, 95295, 214305, 481942, 1083821, 2437364, 5481296, 12326680, 27721007, 62340730, 140195723, 315280889, 709023335, 1594495915, 3585801902, 8063975053, 18134770251, 40782602860, 91714461944
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OFFSET
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0,1
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LINKS
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Alois P. Heinz, Table of n, a(n) for n = 0..1000
D. W. Boyd, Linear recurrence relations for some generalized Pisot sequences, Advances in Number Theory ( Kingston ON, 1991) 333-340, Oxford Sci. Publ., Oxford Univ. Press, New York, 1993.
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MAPLE
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a:= proc(n) option remember; `if`(n<2, [3, 6][n+1],
1 +floor(a(n-1)^2/a(n-2)))
end:
seq(a(n), n=0..40); # Alois P. Heinz, May 05 2014
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MATHEMATICA
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a[n_] := a[n] = Switch[n, 0, 3, 1, 6, _, 1 + Floor[a[n-1]^2/a[n-2]]];
a /@ Range[0, 40] (* Jean-François Alcover, Nov 16 2020, after Alois P. Heinz *)
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CROSSREFS
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Sequence in context: A071014 A214260 A078061 * A093128 A005313 A213674
Adjacent sequences: A018906 A018907 A018908 * A018910 A018911 A018912
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KEYWORD
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nonn
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AUTHOR
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R. K. Guy
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STATUS
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approved
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