cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A000963 The convergent sequence B_n for the ternary continued fraction (3,1;2,2) of period 2.

Original entry on oeis.org

0, 1, 0, 3, 7, 16, 49, 104, 322, 683, 2114, 4485, 13881, 29450, 91147, 193378, 598500, 1269781, 3929940, 8337783, 25805227, 54748516, 169445269, 359496044, 1112631142
Offset: 0

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References

  • D. N. Lehmer, On ternary continued fractions, Tohoku Math. J., 37 (1933), 436-445.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Maple
    A000963:=z*(-1+4*z**2-7*z**3+2*z**4)/(-1+7*z**2-3*z**4+z**6); # conjectured by Simon Plouffe in his 1992 dissertation
    a:= n-> (Matrix([[16,7,3,0,1,0]]). Matrix(6, (i,j)-> if (i=j-1) then 1 elif j=1 then [0, 7, 0, -3, 0, 1][i] else 0 fi)^n)[1,6]: seq(a(n), n=0..24); # Alois P. Heinz, Aug 26 2008
  • Mathematica
    CoefficientList[Series[(-2x^5+7x^4-4x^3+x)/(-x^6+3x^4-7x^2+1),{x,0,40}],x] (* Vincenzo Librandi, Apr 11 2012 *)
    LinearRecurrence[{0,7,0,-3,0,1},{0,1,0,3,7,16},30] (* Harvey P. Dale, Sep 06 2021 *)

Formula

G.f.: (-2x^5 + 7x^4 - 4x^3 + x)/(-x^6 + 3x^4 - 7x^2 + 1).