A210739 Triangle of coefficients of polynomials u(n,x) jointly generated with A210740; see the Formula section.
1, 1, 3, 1, 4, 8, 1, 4, 14, 21, 1, 4, 15, 46, 55, 1, 4, 15, 55, 145, 144, 1, 4, 15, 56, 196, 444, 377, 1, 4, 15, 56, 208, 678, 1331, 987, 1, 4, 15, 56, 209, 764, 2282, 3926, 2584, 1, 4, 15, 56, 209, 779, 2762, 7499, 11434, 6765, 1, 4, 15, 56, 209, 780, 2892, 9804, 24141, 32960, 17711
Offset: 1
Examples
First five rows: 1 1 3 1 4 8 1 4 14 21 1 4 15 46 55 First three polynomials u(n,x): 1, 1 + 3*x, 1 + 4*x + 8*x^2.
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := 2 x*u[n - 1, x] + x*v[n - 1, x] + 1; 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[%] (* A210739 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A210740 *)
Formula
u(n,x)=2x*u(n-1,x)+x*v(n-1,x)+1,
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