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.

A210860 Triangle of coefficients of polynomials u(n,x) jointly generated with A210861; see the Formula section of A210861.

Original entry on oeis.org

1, 2, 1, 4, 5, 2, 10, 18, 12, 3, 26, 64, 62, 28, 5, 76, 230, 286, 183, 60, 8, 232, 846, 1298, 1073, 503, 126, 13, 764, 3220, 5832, 5884, 3563, 1288, 255, 21, 2620, 12608, 26436, 31530, 23353, 10956, 3158, 506, 34, 9496, 51084, 121276, 166630
Offset: 1

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Author

Clark Kimberling, Mar 28 2012

Keywords

Comments

Row n ends with F(n), where F=A000045 (Fibonacci numbers).
Column 1: A000085
For a discussion and guide to related arrays, see A208510.

Examples

			First five rows:
   1
   2    1
   4    5    2
  10   18   12    3
  26   64   62   28    5
First three polynomials u(n,x): 1, 2 + x, 4 + 5x + 2x^2.
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 14;
    u[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x];
    v[n_, x_] := (x + n)*u[n - 1, x] + x*v[n - 1, 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[%]   (* A210860 *)
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]   (* A210861 *)

Formula

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

Extensions

Definition clarified by Alonso del Arte and Harvey P. Dale, Dec 17 2012