A209159 Triangle of coefficients of polynomials v(n,x) jointly generated with A209158; see the Formula section.
1, 1, 3, 1, 5, 5, 1, 7, 15, 11, 1, 9, 29, 41, 21, 1, 11, 47, 99, 103, 43, 1, 13, 69, 193, 301, 249, 85, 1, 15, 95, 331, 687, 851, 583, 171, 1, 17, 125, 521, 1349, 2225, 2285, 1337, 341, 1, 19, 159, 771, 2391, 4923, 6735, 5907, 3015, 683, 1, 21, 197, 1089
Offset: 1
Examples
First five rows: 1 1...3 1...5...5 1...7...15...11 1...9...29...41...21 First three polynomials v(n,x): 1, 1 + 3x, 1 + 5x + 5x^2.
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x]; v[n_, x_] := 2 x*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[%] (* A209158 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209159 *)
Formula
u(n,x)=u(n-1,x)+(x+1)*v(n-1,x),
v(n,x)=2x*u(n-1,x)+x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
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