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.

A210877 Triangle of coefficients of polynomials v(n,x) jointly generated with A210876; see the Formula section.

Original entry on oeis.org

1, 0, 3, 0, 3, 4, 0, 2, 8, 5, 0, 2, 6, 17, 6, 0, 2, 5, 18, 31, 7, 0, 2, 5, 14, 47, 51, 8, 0, 2, 5, 13, 41, 107, 78, 9, 0, 2, 5, 13, 35, 115, 218, 113, 10, 0, 2, 5, 13, 34, 98, 296, 407, 157, 11, 0, 2, 5, 13, 34, 90, 276, 695, 709, 211, 12, 0, 2, 5, 13, 34, 89, 244, 750
Offset: 1

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Author

Clark Kimberling, Mar 30 2012

Keywords

Comments

For n>2, each row begins with 0 and ends with n+1. If the term in row n and column k is denoted by U(n,k), then U(n,n-2)=A105163(n-1).
Row sums: A000225 (-1+2^n)
Alternating row sums: A137470
Limiting row: 0,2,5,13,34,89,..., even-indexed Fibonacci numbers
For a discussion and guide to related arrays, see A208510.

Examples

			First six rows:
1
1...2
1...1...3
1...1...3...4
1...1...2...8...5
1...1...2...6...17...6
First three polynomials v(n,x): 1, 1 + 2x, 1 + x + 3x^2
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 14;
    u[n_, x_] := x*u[n - 1, x] + v[n - 1, x] + 1;
    v[n_, x_] := x*u[n - 1, x] + x*v[n - 1, x] + x;
    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[%]    (* A210876 *)
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]    (* A210877 *)
    Table[u[n, x] /. x -> 1, {n, 1, z}]  (* A000225 *)
    Table[v[n, x] /. x -> 1, {n, 1, z}]  (* A000225 *)
    Table[u[n, x] /. x -> -1, {n, 1, z}] (* A077973 *)
    Table[v[n, x] /. x -> -1, {n, 1, z}] (* A137470 *)

Formula

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