login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A048588 Pisot sequence L(7,8). 2
7, 8, 10, 13, 17, 23, 32, 45, 64, 92, 133, 193, 281, 410, 599, 876, 1282, 1877, 2749, 4027, 5900, 8645, 12668, 18564, 27205, 39869, 58429, 85630, 125495, 183920, 269546, 395037, 578953, 848495, 1243528, 1822477, 2670968, 3914492, 5736965, 8407929, 12322417 (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 Pisot sequences

FORMULA

a(n) = 2*a(n-1) - a(n-2) + a(n-3) - a(n-4) (holds at least up to n = 72000 but is not known to hold in general).

MAPLE

L := proc(a0, a1, n)

    option remember;

    if n = 0 then

        a0 ;

    elif n = 1 then

        a1;

    else

        ceil( procname(a0, a1, n-1)^2/procname(a0, a1, n-2)) ;

    end if;

end proc:

A048588 := proc(n)

    L(7, 8, n) ;

end proc: # R. J. Mathar, Feb 12 2016

MATHEMATICA

RecurrenceTable[{a[0] == 7, a[1] == 8, a[n] == Ceiling[a[n - 1]^2/a[n - 2]]}, a, {n, 0, 50}] (* Bruno Berselli, Feb 05 2016 *)

PROG

(MAGMA) Lxy:=[7, 8]; [n le 2 select Lxy[n] else Ceiling(Self(n-1)^2/Self(n-2)): n in [1..50]]; // 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, 7, 8) \\ Colin Barker, Aug 07 2016

CROSSREFS

See A008776 for definitions of Pisot sequences.

Sequence in context: A067529 A080113 A243078 * A141676 A127164 A153972

Adjacent sequences:  A048585 A048586 A048587 * A048589 A048590 A048591

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 June 25 05:41 EDT 2019. Contains 324346 sequences. (Running on oeis4.)