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.

A099272 Unsigned member r=-14 of the family of Chebyshev sequences S_r(n) defined in A092184.

Original entry on oeis.org

0, 1, 14, 225, 3584, 57121, 910350, 14508481, 231225344, 3685097025, 58730327054, 936000135841, 14917271846400, 237740349406561, 3788928318658574, 60385112749130625, 962372875667431424, 15337580897929772161, 244438921491208923150, 3895685162961412998241
Offset: 0

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Author

Wolfdieter Lang, Oct 18 2004

Keywords

Comments

((-1)^(n+1))*a(n) = S_{-14}(n), n>=0, defined in A092184.

Crossrefs

Cf. A001081.

Programs

  • Maple
    f:= n -> (orthopoly[T](n,8)-(-1)^n)/9:
    map(f, [$0..20]); # Robert Israel, Jun 04 2018
  • Mathematica
    CoefficientList[Series[x (1-x)/(1-15 x-15 x^2+x^3),{x,0,33}],x] (* Vincenzo Librandi, Jun 05 2018 *)

Formula

a(n) = (T(n, 8)-(-1)^n)/9, with Chebyshev's polynomials of the first kind evaluated at x=8: T(n, 8)=A001081(n)=((8+3*sqrt(7))^n + (8-3*sqrt(7))^n)/2.
a(n) = 16*a(n-1)-a(n-2)+2*(-1)^(n+1), n>=2, a(0)=0, a(1)=1.
a(n) = 15*a(n-1) + 15*a(n-2) - a(n-3), n>=3, a(0)=0, a(1)=1, a(2)=14.
G.f.: x*(1-x)/((1+x)*(1-16*x+x^2)) = x*(1-x)/(1-15*x-15*x^2+x^3) (from the Stephan link, see A092184).