A209167 Triangle of coefficients of polynomials v(n,x) jointly generated with A209166; see the Formula section.
1, 2, 2, 3, 5, 3, 5, 12, 12, 5, 8, 25, 35, 25, 8, 13, 50, 89, 89, 50, 13, 21, 96, 207, 263, 207, 96, 21, 34, 180, 455, 698, 698, 455, 180, 34, 55, 331, 959, 1719, 2073, 1719, 959, 331, 55, 89, 600, 1959, 4011, 5643, 5643, 4011, 1959, 600, 89, 144, 1075
Offset: 1
Examples
First five rows: 1 2 2 3 5 3 5 12 12 5 8 25 35 25 8 First three polynomials v(n,x): 1, 2 + 2*x, 3 + 5*x + 3*x^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_] := (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[%] (* A209166 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209167 *)
Formula
u(n,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.
Comments