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A048626 Pisot sequence P(6,9). 2
6, 9, 13, 19, 28, 41, 60, 88, 129, 189, 277, 406, 595, 872, 1278, 1873, 2745, 4023, 5896, 8641, 12664, 18560, 27201, 39865, 58425, 85626, 125491, 183916, 269542, 395033, 578949, 848491, 1243524, 1822473, 2670964, 3914488, 5736961, 8407925, 12322413, 18059374 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (1,0,1).

FORMULA

a(n) = a(n-1) + a(n-3) (Checked up to n = 1000)

a(n) = A048625(n+1). - R. J. Mathar, Oct 15 2008

MATHEMATICA

LinearRecurrence[{1, 0, 1}, {6, 9, 13}, 42] (* Robert G. Wilson v, Jul 12 2014 *)

PROG

(PARI) pisotP(nmax, a1, a2) = {

  a=vector(nmax); a[1]=a1; a[2]=a2;

  for(n=3, nmax, a[n] = ceil(a[n-1]^2/a[n-2]-1/2));

  a

}

pisotP(50, 6, 9) \\ Colin Barker, Aug 08 2016

CROSSREFS

Subsequence of A048625, A000930. See A008776 for definitions of Pisot sequences.

Cf. A020721.

Sequence in context: A315968 A315969 A092949 * A002598 A315970 A315971

Adjacent sequences:  A048623 A048624 A048625 * A048627 A048628 A048629

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified December 7 05:14 EST 2019. Contains 329839 sequences. (Running on oeis4.)