OFFSET
0,1
REFERENCES
Shalosh B. Ekhad, N. J. A. Sloane and Doron Zeilberger, Automated Proof (or Disproof) of Linear Recurrences Satisfied by Pisot Sequences, Preprint, 2016.
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.
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)
FORMULA
Theorem: a(0)=4, a(1)=14, a(2)=49; for n>2, a(n) = 4*a(n-1)-2*a(n-2)+a(n-3). Proved using the PtoRv program of Ekhad-Sloane-Zeilberger. (Conjectured by Harvey P. Dale, May 02 2012.) - N. J. A. Sloane, Sep 09 2016
MATHEMATICA
RecurrenceTable[{a[0] == 4, a[1] == 14, a[n] == Floor[a[n-1]^2/a[n-2] + 1/2]}, a , {n, 30}] (* Harvey P. Dale, May 02 2012 *)
PROG
(Magma) I:=[4, 14]; [n le 2 select I[n] else Floor(Self(n-1)^2/Self(n-2)+1/2): n in [1..25]]; // Bruno Berselli, Sep 03 2013
(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, 4, 14) \\ Colin Barker, Jul 27 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved