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.

A210792 Triangle of coefficients of polynomials v(n,x) jointly generated with A210791; see the Formula section.

Original entry on oeis.org

1, 1, 2, 1, 5, 3, 1, 10, 11, 5, 1, 19, 28, 25, 8, 1, 36, 62, 81, 50, 13, 1, 69, 129, 218, 193, 98, 21, 1, 134, 261, 533, 597, 442, 185, 34, 1, 263, 522, 1235, 1631, 1559, 952, 343, 55, 1, 520, 1040, 2773, 4129, 4763, 3758, 1985, 625, 89, 1, 1033, 2071
Offset: 1

Views

Author

Clark Kimberling, Mar 26 2012

Keywords

Comments

Row n starts with 1 and ends with F(n+1), where F=A000045 (Fibonacci numbers).
Column 2: A052944.
Row sums: A000244 (powers of 3).
Alternating row sums: A001333.
For a discussion and guide to related arrays, see A208510.
Subtriangle of the triangle given by (1, 0, 1/2, 3/2, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (0, 2, -1/2, -1/2, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - Philippe Deléham, Mar 29 2012

Examples

			First five rows:
  1;
  1,  2;
  1,  5,  3;
  1, 10, 11,  5;
  1, 19, 28, 25,  8;
First three polynomials v(n,x):
  1
  1 + 2x
  1 + 5x + 3x^2
From _Philippe Deléham_, Mar 29 2012: (Start)
(1, 0, 1/2, 3/2, 0, 0, 0, ...) DELTA (0, 2, -1/2, -1/2, 0, 0, 0, ...) begins:
  1;
  1,   0;
  1,   2,   0;
  1,   5,   3,   0;
  1,  10,  11,   5,   0;
  1,  19,  28,  25,   8,   0;
  1,  36,  62,  81,  50,  13,   0;
  1,  69, 129, 218, 193,  98,  21,   0; (End)
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 16;
    u[n_, x_] := u[n - 1, x] + (x + j)*v[n - 1, x] + c;
    d[x_] := h + x; e[x_] := p + x;
    v[n_, x_] := d[x]*u[n - 1, x] + e[x]*v[n - 1, x] + f;
    j = 0; c = 0; h = -1; p = 2; f = 0;
    Table[Expand[u[n, x]], {n, 1, z/2}]
    Table[Expand[v[n, x]], {n, 1, z/2}]
    cu = Table[CoefficientList[u[n, x], x], {n, 1, z}];
    TableForm[cu]
    Flatten[%]    (* A210791 *)
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]    (* A210792 *)
    Table[u[n, x] /. x -> 1, {n, 1, z}]   (* A007051 *)
    Table[v[n, x] /. x -> 1, {n, 1, z}]   (* A000244 *)
    Table[u[n, x] /. x -> -1, {n, 1, z}]  (* A001129 *)
    Table[v[n, x] /. x -> -1, {n, 1, z}]  (* A001333 *)

Formula

u(n,x) = u(n-1,x) + x*v(n-1,x),
v(n,x) = (x-1)*u(n-1,x) + (x+2)*v(n-1,x),
where u(1,x)=1, v(1,x)=1.
From Philippe Deléham, Mar 29 2012: (Start)
As DELTA-triangle T(n,k) with 0 <= k <= n:
G.f.: (1 - 2*x - y*x + 3*y*x^2 - y^2*x^2)/(1 - 3*x - y*x + 2*x^2 + 2*y*x^2 - y^2*x^2).
T(n,k) = 3*T(n-1,k) + T(n-1,k-1) - 2*T(n-2,k) - 2*T(n-2,k-1) + T(n-2,k-2), T(0,0) = T(1,0) = T(2,0) = 1, T(2,1) = 2, T(1,1) = T(2,2) = 0 and T(n,k) = 0 if k < 0 or if k > n. (End)