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.

A210601 Triangle of coefficients of polynomials v(n,x) jointly generated with A210600; see the Formula section.

Original entry on oeis.org

1, 3, 2, 6, 9, 4, 11, 26, 24, 8, 19, 63, 89, 60, 16, 32, 138, 265, 270, 144, 32, 53, 284, 693, 949, 760, 336, 64, 87, 560, 1664, 2870, 3072, 2032, 768, 128, 142, 1071, 3761, 7840, 10521, 9272, 5232, 1728, 256, 231, 2002, 8127, 19896, 32143, 35418
Offset: 1

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Author

Clark Kimberling, Mar 24 2012

Keywords

Comments

Row n starts with n and ends with an even-indexed Fibonacci number. For a discussion and guide to related arrays, see A208510.

Examples

			First five rows:
1
3....2
6....9....4
11...26...24...8
19...63...89...60...16
First three polynomials v(n,x): 1, 3 + 2x, 6 + 9x + 4x^2
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 16;
    u[n_, x_] := x*u[n - 1, x] + (x + 1)*v[n - 1, x] + 1;
    v[n_, x_] := (x + 1)*u[n - 1, x] + (x + 1)*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[%]    (* A210600 *)
    Table[Expand[v[n, x]], {n, 1, z}]
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]    (* A210601 *)

Formula

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