A209558 Triangle of coefficients of polynomials v(n,x) jointly generated with A209557; see the Formula section.
1, 2, 2, 2, 5, 4, 3, 7, 11, 8, 3, 13, 21, 23, 16, 4, 15, 44, 57, 47, 32, 4, 24, 60, 129, 145, 95, 64, 5, 26, 108, 207, 346, 353, 191, 128, 5, 38, 130, 405, 646, 875, 833, 383, 256, 6, 40, 212, 545, 1345, 1877, 2124, 1921, 767, 512, 6, 55, 240, 965, 2021
Offset: 1
Examples
First five rows: 1 2...2 2...5...4 3...7...11...8 3...13...21...23...16 First three polynomials v(n,x): 1, 2 + 2x , 2+ 5x + 4x^2 .
Programs
-
Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := x*u[n - 1, x] + v[n - 1, x]; v[n_, x_] := u[n - 1, x] + 2 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[%] (* A209557 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209558 *)
Formula
u(n,x)=x*u(n-1,x)+v(n-1,x),
v(n,x)=u(n-1,x)+2x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
Comments