A209697 Triangle of coefficients of polynomials u(n,x) jointly generated with A209698; see the Formula section.

1, 0, 2, 0, 2, 4, 0, 3, 6, 8, 0, 4, 10, 16, 16, 0, 5, 15, 30, 40, 32, 0, 6, 21, 50, 84, 96, 64, 0, 7, 28, 77, 154, 224, 224, 128, 0, 8, 36, 112, 258, 448, 576, 512, 256, 0, 9, 45, 156, 405, 810, 1248, 1440, 1152, 512, 0, 10, 55, 210, 605, 1362, 2420, 3360, 3520

Offset: 1

Author

Clark Kimberling, Mar 12 2012

Keywords

• nonn
• tabl

Comments

For a discussion and guide to related arrays, see A208510.

Examples

			First five rows:
1
0...2
0...2....4
0...3....6...8
0...4...10...16...16
First three polynomials v(n,x): 1, 2x, 2x + 4x^2.
		

Crossrefs

Cf. A209698, A208510.

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];
v[n_, x_] := x*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[%]   (* A209697 *)
Table[Expand[v[n, x]], {n, 1, z}]
cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
TableForm[cv]
Flatten[%]   (* A209698 *)

Formula

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

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

where u(1,x)=1, v(1,x)=1.