A209166 Triangle of coefficients of polynomials u(n,x) jointly generated with A209167; see the Formula section.
1, 2, 1, 4, 5, 2, 7, 13, 10, 3, 12, 30, 34, 20, 5, 20, 63, 94, 80, 38, 8, 33, 126, 233, 258, 177, 71, 13, 54, 243, 536, 728, 647, 374, 130, 21, 88, 457, 1171, 1881, 2043, 1527, 765, 235, 34, 143, 843, 2461, 4559, 5835, 5319, 3443, 1525, 420, 55, 232
Offset: 1
Examples
First five rows: 1 2....1 5....5....1 11...15...6....1 23...41...27...9...1 First three polynomials v(n,x): 1, 2 + x, 5 + 5x + 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