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A014003 Pisot sequence E(9,15), a(n) = floor( a(n-1)^2/a(n-2) + 1/2 ). 1
9, 15, 25, 42, 71, 120, 203, 343, 580, 981, 1659, 2806, 4746, 8027, 13576, 22961, 38834, 65680, 111085, 187879, 317761, 537431, 908960, 1537329, 2600093, 4397552, 7437605, 12579264, 21275381, 35983173, 60858545, 102930403, 174086776, 294433954, 497977820 (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, Some integer sequences related to the Pisot sequences, Acta Arithmetica, 34 (1979), 295-305.

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.

FORMULA

Known not to satisfy any linear recurrence.

PROG

(PARI) pisotE(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]+1/2));

  a

}

pisotE(50, 9, 15) \\ Colin Barker, Jul 28 2016

CROSSREFS

Sequence in context: A251415 A109888 A193227 * A333788 A082549 A013569

Adjacent sequences:  A014000 A014001 A014002 * A014004 A014005 A014006

KEYWORD

nonn

AUTHOR

Simon Plouffe

STATUS

approved

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Last modified August 3 14:40 EDT 2021. Contains 346438 sequences. (Running on oeis4.)