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.

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A173435 Inverse binomial transform of A143025, assuming offset zero there.

Original entry on oeis.org

8, -6, 12, -25, 52, -106, 212, -420, 832, -1656, 3312, -6640, 13312, -26656, 53312, -106560, 212992, -425856, 851712, -1703680, 3407872, -6816256, 13632512, -27264000, 54525952, -109049856, 218099712, -436203520, 872415232, -1744838656, 3489677312, -6979338240
Offset: 0

Views

Author

Paul Curtz, Feb 18 2010

Keywords

Comments

Inverse binomial transform of 8, 2, 8, 1, 8, 2 ,8, 1,... with a(0)=8, a(1)=2 etc.

Programs

  • Mathematica
    Join[{8},LinearRecurrence[{-4,-6,-4},{-6,12,-25},40]] (* Harvey P. Dale, Sep 25 2013 *)

Formula

a(n)= -4*a(n-1) -6*a(n-2) -4*a(n-3), n>3. G.f.: (26*x+36*x^2+19*x^3+8)/( (2*x+1) * (2*x^2+2*x+1)). [R. J. Mathar, Mar 10 2010]
a(n+1) +2*a(n) = (-1)^(n+1)*A009545(n-1), n > 0.

Extensions

Extended by R. J. Mathar, Mar 10 2010

A191897 Coefficients of the Z(n,x) polynomials; Z(0,x) = 1, Z(1,x) = x and Z(n,x) = x*Z(n-1,x) - 2*Z(n-2,x), n >= 2.

Original entry on oeis.org

1, 1, 0, 1, 0, -2, 1, 0, -4, 0, 1, 0, -6, 0, 4, 1, 0, -8, 0, 12, 0, 1, 0, -10, 0, 24, 0, -8, 1, 0, -12, 0, 40, 0, -32, 0, 1, 0, -14, 0, 60, 0, -80, 0, 16, 1, 0, -16, 0, 84, 0, -160, 0, 80, 0, 1, 0, -18, 0, 112, 0, -280, 0, 240, 0, -32
Offset: 0

Views

Author

Paul Curtz, Jun 19 2011

Keywords

Comments

The coefficients of the Z(n,x) polynomials by decreasing exponents, see the formulas, define this triangle.

Examples

			The first few rows of the coefficients of the Z(n,x) are
  1;
  1,    0;
  1,    0,   -2;
  1,    0,   -4,    0;
  1,    0,   -6,    0,    4;
  1,    0,   -8,    0,   12,    0;
  1,    0,  -10,    0,   24,    0,   -8;
  1,    0,  -12,    0,   40,    0,  -32,    0;
  1,    0,  -14,    0,   60,    0,  -80,    0,   16;
  1,    0,  -16,    0,   84,    0, -160,    0,   80,    0;
		

Crossrefs

Row sums: A107920(n+1). Main diagonal: A077966(n).
Z(n,x=1) = A107920(n+1), Z(n,x=2) = A009545(n+1),
Z(n,x=3) = A000225(n+1), Z(n,x=4) = A007070(n),
Z(n,x=5) = A107839(n), Z(n,x=6) = A154244(n),
Z(n,x=7) = A186446(n), Z(n,x=8) = A190975(n+1),
Z(n,x=9) = A190979(n+1), Z(n,x=10) = A190869(n+1).
Row sum without sign: A113405(n+1).

Programs

  • Maple
    nmax:=10: Z(0, x):=1 : Z(1, x):=x: for n from 2 to nmax do Z(n, x) := x*Z(n-1, x) - 2*Z(n-2, x) od: for n from 0 to nmax do for k from 0 to n do T(n, k) := coeff(Z(n, x), x, n-k) od: od: seq(seq(T(n, k), k=0..n), n=0..nmax); # Johannes W. Meijer, Jun 27 2011, revised Nov 29 2012
  • Mathematica
    a[n_, k_] := If[OddQ[k], 0, 2^(k/2)*Coefficient[ ChebyshevU[n, x/2], x, n-k]]; Flatten[ Table[ a[n, k], {n, 0, 10}, {k, 0, n}]] (* Jean-François Alcover, Aug 02 2012, from 2nd formula *)

Formula

Z(0,x) = 1, Z(1,x) = x and Z(n,x) = x*Z(n-1,x) - 2*Z(n-2,x), n >= 2.
a(n,k) = A077957(k) * A053119(n,k). - Paul Curtz, Sep 30 2011

Extensions

Edited and information added by Johannes W. Meijer, Jun 27 2011

A373392 Inverse binomial transform of A135318.

Original entry on oeis.org

1, 0, 0, 1, -2, 3, -4, 7, -18, 51, -136, 339, -814, 1935, -4620, 11111, -26842, 64923, -156944, 379067, -915078, 2208711, -5331476, 12870639, -31072754, 75018195, -181113240, 437248771, -1055610782, 2548462143, -6152518684, 14853483127, -35859484938, 86572485771
Offset: 0

Views

Author

Paul Curtz, Jun 03 2024

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{-4, -5, -2, 2}, {1, 0, 0, 1}, 35] (* Amiram Eldar, Jun 09 2024 *)
  • PARI
    a(n) = ((-([-2,-1;-1, 0]^(n-2))[2, 1]) - 2*((I-1)^(n-4) + (-I-1)^(n-4)))/3; \\ Thomas Scheuerle, Jun 04 2024

Formula

G.f.: (1 + 4*x + 5*x^2 + 3*x^3) / ( (1 + 2*x - x^2) * (1 + 2*x + 2*x^2) ).
E.g.f.: 1/6*exp(-x)*(2*cos(-x) + 4*cosh(sqrt(2)*-x) - 3*sqrt(2)*sinh(sqrt(2)*-x)).
a(n) = -4*a(n-1) - 5*a(n-2) - 2*a(n-3) + 2*a(n-4), for n > 4.
a(n) = (-1)^(n+1)*(A000129(n-2) + 2*A009545(n-2))/3, for n > 2. - Thomas Scheuerle, Jun 04 2024
a(n) = A373358(n-3) - (-1)^n*A009545(n+2) for n > 2.
Previous Showing 51-53 of 53 results.