A210227 Triangle of coefficients of polynomials u(n,x) jointly generated with A210228; see the Formula section.
1, 2, 1, 2, 6, 1, 2, 8, 16, 1, 2, 8, 32, 38, 1, 2, 8, 36, 112, 84, 1, 2, 8, 36, 156, 348, 178, 1, 2, 8, 36, 164, 620, 988, 368, 1, 2, 8, 36, 164, 732, 2244, 2624, 750, 1, 2, 8, 36, 164, 748, 3108, 7468, 6632, 1516, 1, 2, 8, 36, 164, 748, 3380, 12348, 23164
Offset: 1
Examples
First five rows: 1 2...1 2...6...1 2...8...16...1 2...8...32...38...1 First three polynomials u(n,x): 1, 2 + x, 2 + 6x + x^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] + v[n - 1, x] + 1; v[n_, x_] := 2 x*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[%] (* A210225 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A210226 *)
Formula
u(n,x)=x*u(n-1,x)+v(n-1,x)+1,
v(n,x)=2x*u(n-1,x)+2x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
Comments