login
Triangle of coefficients of polynomials u(n,x) jointly generated with A209770; see the Formula section.
3

%I #6 Mar 30 2012 18:58:15

%S 1,1,2,3,5,3,5,12,11,5,9,26,34,24,8,15,53,88,86,48,13,25,104,210,258,

%T 200,93,21,41,198,470,695,680,440,175,34,67,369,1007,1737,2043,1671,

%U 929,323,55,109,676,2085,4107,5625,5529,3895,1901,587,89,177

%N Triangle of coefficients of polynomials u(n,x) jointly generated with A209770; see the Formula section.

%C Column 1: A001595

%C Row n ends with F(n+1), where F=A000045 (Fibonacci numbers).

%C Row sums: 1,3,11,33,101,303,911,2733,... A081250

%C Alternating row sums: 1,-1,1,-1,1,-1,... A033999

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

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

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

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

%e First five rows:

%e 1

%e 1...2

%e 3...5....3

%e 5...12...11...5

%e 9...26...34...24...8

%e First three polynomials u(n,x): 1, 1 + 2x, 3 + 5x + 3x^2.

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

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

%t v[n_, x_] := (x + 1)*u[n - 1, x] + 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[%] (* A209769 *)

%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[%] (* A209770 *)

%Y Cf. A209770, A208510.

%K nonn,tabl

%O 1,3

%A _Clark Kimberling_, Mar 15 2012