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.

A210550 Triangle of coefficients of polynomials v(n,x) jointly generated with A210549; see the Formula section.

Original entry on oeis.org

1, 2, 2, 2, 6, 4, 2, 7, 16, 8, 2, 7, 23, 40, 16, 2, 7, 24, 71, 96, 32, 2, 7, 24, 81, 207, 224, 64, 2, 7, 24, 82, 266, 575, 512, 128, 2, 7, 24, 82, 279, 843, 1535, 1152, 256, 2, 7, 24, 82, 280, 939, 2572, 3967, 2560, 512, 2, 7, 24, 82, 280, 955, 3102, 7565, 9983
Offset: 1

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Author

Clark Kimberling, Mar 22 2012

Keywords

Comments

Row sums: -1+odd-indexed Fibonacci numbers
For a discussion and guide to related arrays, see A208510.

Examples

			First five rows:
2
2...2
2...6...4
2...7...16....8
2...7...28....40...16
First three polynomials v(n,x): 2, 2 + 2x , 2 + 6x + 4x^2.
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 16;
    u[n_, x_] := x*u[n - 1, x] + x*v[n - 1, x] + 1;
    v[n_, x_] := u[n - 1, x] + 2 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[%]    (* A210549 *)
    Table[Expand[v[n, x]], {n, 1, z}]
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]    (* A210550 *)

Formula

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