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A019495 Define the sequence T(a(0),a(1)) by a(n+2) is the greatest integer such that a(n+2)/a(n+1) < a(n+1)/a(n) for n >= 0. This is T(4,11). 2
4, 11, 30, 81, 218, 586, 1575, 4233, 11376, 30572, 82159, 220793, 593356, 1594576, 4285239, 11516085, 30948148, 83169572, 223508615, 600653577, 1614187084, 4337941272, 11657715927, 31328764525, 84192434676, 226257439900, 608040726071, 1634039193249 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Colin Barker, 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.

MAPLE

a:= proc(n) option remember;

      `if`(n<2, [4, 11][n+1], ceil(a(n-1)^2/a(n-2))-1)

    end:

seq(a(n), n=0..30);  # Alois P. Heinz, Sep 18 2015

MATHEMATICA

a = {4, 11}; Do[AppendTo[a, Floor[a[[n]]^2/a[[n - 1]]]], {n, 2, 27}];

a (* Michael De Vlieger, Sep 18 2015 *)

PROG

(PARI) T(a0, a1, maxn) = a=vector(maxn); a[1]=a0; a[2]=a1; for(n=3, maxn, a[n]=floor(a[n-1]^2/a[n-2])); a

T(4, 11, 100) \\ Colin Barker, Sep 18 2015

(MAGMA) Iv:=[4, 11]; [n le 2 select Iv[n] else Floor(Self(n-1)^2/Self(n-2)): n in [1..40]]; // Bruno Berselli, Feb 04 2016

CROSSREFS

See A008776 for definitions of Pisot sequences.

Sequence in context: A110034 A114726 A128098 * A019496 A021006 A078141

Adjacent sequences:  A019492 A019493 A019494 * A019496 A019497 A019498

KEYWORD

nonn

AUTHOR

R. K. Guy

STATUS

approved

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Last modified February 25 03:06 EST 2018. Contains 299630 sequences. (Running on oeis4.)