login
Triangle of coefficients of polynomials u(n,x) jointly generated with A209560; see the Formula section.
4

%I #8 Apr 26 2016 12:07:07

%S 1,1,1,3,2,1,5,8,3,1,9,17,15,4,1,15,38,39,24,5,1,25,76,104,74,35,6,1,

%T 41,149,242,229,125,48,7,1,67,282,543,607,440,195,63,8,1,109,524,1159,

%U 1531,1308,769,287,80,9,1,177,957,2401,3631,3660,2533,1253,404

%N Triangle of coefficients of polynomials u(n,x) jointly generated with A209560; see the Formula section.

%C For a discussion and guide to related arrays, see A208510.

%F u(n,x)=x*u(n-1,x)+v(n-1,x),

%F v(n,x)=u(n-1,x)+(x+1)*v(n-1,x) +1,

%F where u(1,x)=1, v(1,x)=1.

%e First five rows:

%e 1

%e 1...1

%e 3...2....1

%e 5...8....3....1

%e 9...17...15...4...1

%e First three polynomials v(n,x): 1, 1 + x, 3 + 2x + x^2.

%t u[1, x_] := 1; v[1, x_] := 1; z = 16;

%t u[n_, x_] := x*u[n - 1, x] + v[n - 1, x];

%t v[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x] + 1;

%t Table[Expand[u[n, x]], {n, 1, z/2}]

%t Table[Expand[v[n, x]], {n, 1, z/2}]

%t cu = Table[CoefficientList[u[n, x], x], {n, 1, z}];

%t TableForm[cu]

%t Flatten[%] (* A209559 *)

%t Table[Expand[v[n, x]], {n, 1, z}]

%t cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];

%t TableForm[cv]

%t Flatten[%] (* A209560 *)

%Y Cf. A209560, A208510.

%K nonn,tabl

%O 1,4

%A _Clark Kimberling_, Mar 10 2012