A208914 Triangle of coefficients of polynomials v(n,x) jointly generated with A208913; see the Formula section.
1, 2, 2, 3, 4, 4, 4, 6, 16, 8, 5, 8, 40, 32, 16, 6, 10, 80, 80, 96, 32, 7, 12, 140, 160, 336, 192, 64, 8, 14, 224, 280, 896, 672, 512, 128, 9, 16, 336, 448, 2016, 1792, 2304, 1024, 256, 10, 18, 480, 672, 4032, 4032, 7680, 4608, 2560, 512, 11, 20, 660, 960
Offset: 1
Examples
First five rows: 1 2...2 3...4...4 4...6...16...8 5...8...40...32...16 First five polynomials v(n,x): 1 2 + 2x 3 + 4x + 4x^2 4 + 6x + 16x^2 + 8x^3 5 + 8x + 40x^2 + 32x^3 + 16x^4
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_] := 2 x*u[n - 1, 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[%] (* A208913 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A208914 *)
Formula
u(n,x)=u(n-1,x)+2x*v(n-1,x),
v(n,x)=2x*u(n-1,x)+v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
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