A209772 Triangle of coefficients of polynomials v(n,x) jointly generated with A209771; see the Formula section.
1, 2, 2, 2, 5, 4, 3, 9, 14, 8, 3, 14, 32, 36, 16, 4, 20, 60, 100, 88, 32, 4, 27, 100, 220, 288, 208, 64, 5, 35, 154, 420, 728, 784, 480, 128, 5, 44, 224, 728, 1568, 2240, 2048, 1088, 256, 6, 54, 312, 1176, 3024, 5376, 6528, 5184, 2432, 512, 6, 65, 420
Offset: 1
Examples
First five rows: 1 2...2 2...5....4 3...9....14...8 3...14...32...36...16 First three polynomials v(n,x): 1, 2 + 2x , 2 + 5x + 4x^2.
Programs
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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] + x*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[%] (* A209771 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209772 *)
Formula
u(n,x)=x*u(n-1,x)+(x+1)*v(n-1,x),
v(n,x)=(x+1)*u(n-1,x)+x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
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