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.

A210878 Triangle of coefficients of polynomials u(n,x) jointly generated with A210879; see the Formula section.

Original entry on oeis.org

1, 0, 3, 0, 4, 7, 0, 2, 14, 17, 0, 2, 12, 46, 41, 0, 2, 8, 54, 140, 99, 0, 2, 8, 42, 212, 408, 239, 0, 2, 8, 34, 200, 758, 1154, 577, 0, 2, 8, 34, 160, 866, 2544, 3194, 1393, 0, 2, 8, 34, 144, 754, 3448, 8154, 8696, 3363, 0, 2, 8, 34, 144, 642, 3400, 12850
Offset: 1

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Author

Clark Kimberling, Mar 30 2012

Keywords

Comments

Leading coefficient of u(n,x): A001333
Limiting row: 0,2,8,34,144,610,...(Fibonacci numbers)
For a discussion and guide to related arrays, see A208510.

Examples

			First six rows:
1
0...3
0...4...7
0...2...14...17
0...2...12...46...41
0...2...8....54...140...99
First three polynomials u(n,x): 1, 3x, 4x + 7x^2.
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 14;
    u[n_, x_] := x*u[n - 1, x] + 2 x*v[n - 1, x];
    v[n_, x_] := (x + 1)*u[n - 1, x] + 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[%]    (* A210878 *)
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]    (* A210879 *)

Formula

u(n,x)=x*u(n-1,x)+2x*v(n-1,x),
v(n,x)=(x+1)*u(n-1,x)+x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.