A209706 Triangle of coefficients of polynomials v(n,x) jointly generated with A209705; see the Formula section.
1, 3, 2, 4, 7, 4, 5, 14, 18, 8, 6, 23, 46, 44, 16, 7, 34, 92, 136, 104, 32, 8, 47, 160, 320, 376, 240, 64, 9, 62, 254, 640, 1016, 992, 544, 128, 10, 79, 378, 1148, 2296, 3024, 2528, 1216, 256, 11, 98, 536, 1904, 4592, 7616, 8576, 6272, 2688, 512, 12, 119
Offset: 1
Examples
First five rows: 1 3...2 4...7....4 5...14...18...8 6...23...46...44...16 First three polynomials v(n,x): 1, 3 + 2x , 4 + 7x + 4x^2.
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 + 1)*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[%] (* A209705 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209706 *)
Formula
u(n,x) = x*u(n-1,x)+x*v(n-1,x),
v(n,x) = (x+1)*u(n-1,x)+(x+1)v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
T(n,k) = 2*T(n-1,k)+2*T(n-1,k-1)-T(n-2,k)-2*T(n-2,k-1), T(1,0)=1, T(2,0)=3, T(2,1)=2, T(3,0)=4, T(3,1)=7, T(3,2)=4, T(n,k)=0 if k<0 or if k>=n. - Philippe Deléham, Dec 27 2013
Comments