A210791 Triangle of coefficients of polynomials u(n,x) jointly generated with A210792; see the Formula section.
1, 1, 1, 1, 2, 2, 1, 3, 7, 3, 1, 4, 17, 14, 5, 1, 5, 36, 42, 30, 8, 1, 6, 72, 104, 111, 58, 13, 1, 7, 141, 233, 329, 251, 111, 21, 1, 8, 275, 494, 862, 848, 553, 206, 34, 1, 9, 538, 1016, 2097, 2479, 2112, 1158, 377, 55, 1, 10, 1058, 2056, 4870, 6608, 6875
Offset: 1
Examples
First five rows: 1; 1, 1; 1, 2, 2; 1, 3, 7, 3; 1, 4, 17, 14, 5; First three polynomials u(n,x): 1 1 + x 1 + 2x + 2x^2. From _Philippe Deléham_, Mar 29 2012: (Start) (1, 0, 0, 2, 0, 0, 0, ...) DELTA (0, 1, 1, -1, 0, 0, 0, ...) begins: 1; 1, 0; 1, 1, 0; 1, 2, 2, 0; 1, 3, 7, 3, 0; 1, 4, 17, 14, 5, 0; 1, 5, 36, 42, 30, 8, 0; 1, 6, 72, 104, 111, 58, 13, 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 = -1; p = 2; 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[%] (* A210791 *) cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A210792 *) Table[u[n, x] /. x -> 1, {n, 1, z}] (* A007051 *) Table[v[n, x] /. x -> 1, {n, 1, z}] (* A000244 *) Table[u[n, x] /. x -> -1, {n, 1, z}] (* A001129 *) Table[v[n, x] /. x -> -1, {n, 1, z}] (* A001333 *)
Formula
u(n,x) = u(n-1,x) + x*v(n-1,x),
v(n,x) = (x-1)*u(n-1,x) + (x+2)*v(n-1,x),
where u(1,x)=1, v(1,x)=1.
From Philippe Deléham, Mar 29 2012: (Start)
As DELTA-triangle T(n,k) with 0 <= k <= n:
G.f.: (1 - 2*x - y*x + 2*y*x^2 - y^2*x^2)/(1 - 3*x - y*x + 2*x^2 + 2*y*x^2 - y^2*x^2).
T(n,k) = 3*T(n-1,k) + T(n-1,k-1) - 2*T(n-2,k) - 2*T(n-2,k-1) + T(n-2,k-2), T(0,0) = T(1,0) = T(2,0) = T(2,1) = 1, T(1,1) = T(2,2) = 0 and T(n,k) = 0 if k < 0 or if k > n. (End)
Comments