A209830 Triangle of coefficients of polynomials u(n,x) jointly generated with A209831; see the Formula section.

1, 1, 2, 1, 5, 5, 1, 7, 18, 13, 1, 10, 35, 59, 34, 1, 12, 61, 147, 185, 89, 1, 15, 90, 302, 558, 564, 233, 1, 17, 129, 527, 1324, 1986, 1685, 610, 1, 20, 170, 854, 2653, 5350, 6761, 4957, 1597, 1, 22, 222, 1278, 4811, 12066, 20383, 22277, 14406, 4181, 1

Offset: 1

Author

Clark Kimberling, Mar 13 2012

Keywords

• nonn
• tabl

Comments

Each row begins with 1 and ends with an odd-indexed Fibonacci number.

Alternating row sums: 1,-1,1,-1,1,-1,1,-1,...

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

Subtriangle of the triangle given by (1, 0, 1/2, -3/2, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (0, 2, 1/2, 1/2, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - Philippe Deléham, Mar 16 2012

Examples

			First five rows:
  1;
  1,  2;
  1,  5,  5;
  1,  7, 18, 13;
  1, 10, 35, 59, 34;
First three polynomials u(n,x):
  1
  1 + 2x
  1 + 5x + 5x^2.
From _Philippe Deléham_, Mar 16 2012: (Start)
(1, 0, 1/2, -3/2, 0, 0, ...) DELTA (0, 2, 1/2, 1/2, 0, 0, ...) begins:
  1;
  1,  0;
  1,  2,  0;
  1,  5,  5,  0;
  1,  7, 18, 13,  0;
  1, 10, 35, 59, 34, 0; (End)
		

Crossrefs

Cf. A209831, A208510.

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];
v[n_, x_] := (x + 1)*u[n - 1, x] + 2 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[%]    (* A209830 *)
Table[Expand[v[n, x]], {n, 1, z}]
cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
TableForm[cv]
Flatten[%]    (* A209831 *)

Formula

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

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

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

As DELTA-triangle with 0 <= k <= n: G.f.: (1+x-3*y*x-3*y*x^2+y^2*x^2)/(1-3*y*x-x^2-2*y*x^2+y^2*x^2). - Philippe Deléham, Mar 16 2012

As DELTA-triangle: T(n,k) = 3*T(n-1,k-1) + T(n-2,k) + 2*T(n-2,k-1) - T(n-2,k-2), T(0,0) = T(1,0) = T(2,0) = 1, T(1,1) = T(2,2) = 0, T(2,1) = 2 and T(n,k) = 0 if k < 0 or if k > n. - Philippe Deléham, Mar 16 2012