login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A276396 Pisot sequence E(30,989), a(n) = floor(a(n-1)^2/a(n-2) + 1/2). 1
30, 989, 32604, 1074844, 35433984, 1168139025, 38509606533, 1269531933775, 41852188998435, 1379725611747520, 45484903162012677, 1499483953941604826, 49432932068022376719, 1629637160449986379665, 53723644615396971780840, 1771087491625747409656874, 58386785286979621920361203, 1924815522816772987855854836 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Satisfies a(n) = 33 a(n - 1) - 2 a(n - 2) + 30 a(n - 3) - 11 a(n - 4) for 4 <= n <= 15888 but not for n = 15889. It is not known if there is a linear recurrence which is valid for all n.

LINKS

Colin Barker, Table of n, a(n) for n = 0..650

S. B. Ekhad, N. J. A. Sloane, D. Zeilberger, Automated proofs (or disproofs) of linear recurrences satisfied by Pisot Sequences, arXiv:1609.05570 [math.NT] (2016)

MATHEMATICA

a[0] = 30; a[1] = 989; a[n_] := a[n] = Floor[a[n-1]^2/a[n-2] + 1/2];

Table[a[n], {n, 0, 17}] (* Jean-Fran├žois Alcover, Oct 10 2018 *)

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(20, 30, 989) \\ Colin Barker, Sep 11 2016

CROSSREFS

For definition of Pisot sequences see A008776.

Sequence in context: A111216 A158672 A268948 * A291070 A004994 A273626

Adjacent sequences:  A276393 A276394 A276395 * A276397 A276398 A276399

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 10 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 5 16:19 EDT 2020. Contains 334852 sequences. (Running on oeis4.)