A208758 Triangle of coefficients of polynomials v(n,x) jointly generated with A208757; see the Formula section.
1, 0, 3, 0, 1, 8, 0, 1, 4, 22, 0, 1, 4, 16, 60, 0, 1, 4, 18, 56, 164, 0, 1, 4, 20, 68, 188, 448, 0, 1, 4, 22, 80, 248, 608, 1224, 0, 1, 4, 24, 92, 312, 864, 1920, 3344, 0, 1, 4, 26, 104, 380, 1152, 2928, 5952, 9136, 0, 1, 4, 28, 116, 452, 1472, 4128, 9696, 18192
Offset: 1
Examples
First five rows: 1; 0, 3; 0, 1, 8; 0, 1, 4, 22; 0, 1, 4, 16, 60; First five polynomials v(n,x): 1 3x x + 8x^2 x + 4x^2 + 22x^3 x + 4x^2 + 16x^3 + 60^x4
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := u[n - 1, x] + 2 x*v[n - 1, x]; v[n_, x_] := x*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[%] (* A208757 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A208758 *)
Formula
u(n,x) = u(n-1,x) + 2x*v(n-1,x),
v(n,x) = x*u(n-1,x) + 2x*v(n-1,x),
where u(1,x)=1, v(1,x)=1.
As triangle T(n,k), 0 <= k <= n: g.f.: (1-x-y*x)/(1-(1+2*y)*x -2*y(y-1)*x^2). - Philippe Deléham, Mar 02 2012
As triangle T(n,k), 0 <= k <= n: T(n,k) = T(n-1,k) + 2*T(n-1,k-1) - 2*T(n-2,k-1) + 2*T(n-2,k-2) with T(0,0) = 1, T(1,0) = 0, T(1,1) = 3 and T(n,k) = 0 if k < 0 or if k > n. - Philippe Deléham, Mar 02 2012
Comments