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.

A133567 A007318 * A133566.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 6, 3, 1, 1, 10, 6, 5, 1, 1, 15, 10, 15, 5, 1, 1, 21, 15, 35, 15, 7, 1, 1, 28, 21, 70, 35, 28, 7, 1, 1, 36, 28, 126, 70, 84, 28, 9, 1, 1, 45, 36, 210, 126, 210, 84, 45, 9, 1
Offset: 1

Views

Author

Gary W. Adamson, Sep 16 2007

Keywords

Comments

Row sums = A083329: (1, 2, 5, 11, 23, 47, 95, ...).
From Clark Kimberling, Feb 28 2012: (Start)
A133567 is jointly generated with A133084 as an array of coefficients of polynomials v(n,x): initially, u(1,x) = v(1,x) = 1; for n > 1, u(n,x) = u(n-1,x) + (x+1)*v(n-1)x and v(n,x) = x*u(n-1,x) + v(n-1,x) + 1. See the Mathematica section. (End)

Examples

			First few rows of the triangle:
  1;
  1,  1;
  1,  3,  1;
  1,  6,  3,  1;
  1, 10,  6,  5,  1;
  1, 15, 10, 15,  5,  1;
  1, 21, 15, 35, 15,  7,  1;
  ...
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 16;
    u[n_, x_] := u[n - 1, x] + x*v[n - 1, x];
    v[n_, x_] := x*u[n - 1, x] + v[n - 1, x] + 1;
    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[%]  (* A133567 *)
    Table[Expand[v[n, x]], {n, 1, z}]
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]  (* A133084 *)
    (* Clark Kimberling, Feb 28 2012 *)

Formula

Binomial transform of triangle A133566.