A209775 Triangle of coefficients of polynomials u(n,x) jointly generated with A209776; see the Formula section.
1, 1, 2, 3, 6, 4, 5, 16, 18, 8, 9, 36, 60, 48, 16, 15, 76, 166, 194, 120, 32, 25, 152, 414, 634, 572, 288, 64, 41, 294, 960, 1822, 2154, 1584, 672, 128, 67, 554, 2114, 4790, 7004, 6752, 4192, 1536, 256, 109, 1024, 4476, 11800, 20560, 24498, 19952
Offset: 1
Examples
First five rows: 1 1...2 3...6....4 5...16...18...8 9...36...60...48...16 First three polynomials u(n,x): 1, 1 + 2x, 3 + 6x + 4x^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] + (x + 1)*v[n - 1, x]; v[n_, x_] := (x + 1)*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[%] (* A209775 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209776 *)
Formula
u(n,x)=x*u(n-1,x)+(x+1)*v(n-1,x),
v(n,x)=(x+1)*u(n-1,x)+(x+1)*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
Comments