A210790 Triangle of coefficients of polynomials v(n,x) jointly generated with A210789; see the Formula section.
1, 1, 2, 1, 2, 3, 1, 4, 5, 5, 1, 4, 10, 10, 8, 1, 6, 14, 24, 20, 13, 1, 6, 21, 38, 52, 38, 21, 1, 8, 27, 65, 96, 109, 71, 34, 1, 8, 36, 92, 176, 224, 220, 130, 55, 1, 10, 44, 136, 280, 446, 500, 434, 235, 89, 1, 10, 55, 180, 440, 772, 1066, 1074, 839, 420, 144, 1
Offset: 1
Examples
First five rows: 1; 1, 2; 1, 2, 3; 1, 4, 5, 5; 1, 4, 10, 10, 8; First three polynomials v(n,x): 1 1 + 2x 1 + 2x + 3x^2. From _Philippe Deléham_, Mar 28 2012: (Start) (1, 0, -1, 0, 0, ...) DELTA (0, 2, -1/2, -1/2, 0, 0, ...) begins: 1; 1, 0; 1, 2, 0; 1, 2, 3, 0; 1, 4, 5, 5, 0; 1, 4, 10, 10, 8, 0; (End)
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := u[n - 1, x] + (x + j)*v[n - 1, x] + c; d[x_] := h + x; e[x_] := p + x; v[n_, x_] := d[x]*u[n - 1, x] + e[x]*v[n - 1, x] + f; j = 0; c = 0; h = 2; p = -1; f = 0; 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[%] (* A210789 *) cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A210790 *) Table[u[n, x] /. x -> 1, {n, 1, z}] (* A006138 *) Table[v[n, x] /. x -> 1, {n, 1, z}] (* A105476 *) Table[u[n, x] /. x -> -1, {n, 1, z}] (* [A000045] *) Table[v[n, x] /. x -> -1, {n, 1, z}] (* [A000045] *)
Formula
u(n,x) = u(n-1,x) + x*v(n-1,x),
v(n,x) = (x+2)*u(n-1,x) + (x-1)*v(n-1,x),
where u(1,x)=1, v(1,x)=1.
From Philippe Deléham, Mar 28 2012: (Start)
As DELTA-triangle T(n,k) with 0 <= k <= n:
G.f.: (1+x-y*x-y^2*x^2)/(1-y*x-x^2-y*x^2-y^2*x^2).
T(n,k) = T(n-1,k-1) + T(n-2,k) + T(n-2,k-1) + T(n-2,k-2), T(0,0) = T(1,0) = T(2,0) = 1, T(2,1) = 2, T(1,1) = T(2,2) = 0 and T(n,k) = 0 if k < 0 or if k > n. (End)
Comments