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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A020736 Pisot sequence L(5,8). 2
5, 8, 13, 22, 38, 66, 115, 201, 352, 617, 1082, 1898, 3330, 5843, 10253, 17992, 31573, 55406, 97230, 170626, 299427, 525457, 922112, 1618193, 2839730, 4983378, 8745218, 15346787, 26931733, 47261896, 82938845, 145547526, 255418102, 448227522, 786584467 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

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

FORMULA

a(n) = 3*a(n-1) - 3*a(n-2) + 2*a(n-3) - a(n-4) (holds at least up to n = 1000 but is not known to hold in general).

MATHEMATICA

RecurrenceTable[{a[0] == 5, a[1] == 8, a[n] == Ceiling[a[n - 1]^2/a[n - 2]]}, a, {n, 0, 40}] (* Bruno Berselli, Feb 05 2016 *)

PROG

(MAGMA) Lxy:=[5, 8]; [n le 2 select Lxy[n] else Ceiling(Self(n-1)^2/Self(n-2)): n in [1..40]]; // Bruno Berselli, Feb 05 2016

(PARI) pisotL(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]));

  a

}

pisotL(50, 5, 8) \\ Colin Barker, Aug 07 2016

CROSSREFS

See A008776 for definitions of Pisot sequences.

Sequence in context: A314468 A111321 A306943 * A314469 A217185 A160421

Adjacent sequences:  A020733 A020734 A020735 * A020737 A020738 A020739

KEYWORD

nonn

AUTHOR

David W. Wilson

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 November 30 17:31 EST 2020. Contains 338807 sequences. (Running on oeis4.)