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Triangle of coefficients of polynomials v(n,x) jointly generated with A209571; see the Formula section.
3

%I #5 Mar 30 2012 18:58:15

%S 1,1,3,1,3,5,1,3,11,7,1,3,11,29,9,1,3,11,41,61,11,1,3,11,41,129,111,

%T 13,1,3,11,41,153,339,183,15,1,3,11,41,153,523,771,281,17,1,3,11,41,

%U 153,571,1571,1569,409,19,1,3,11,41,153,571,2035,4161,2929,571,21

%N Triangle of coefficients of polynomials v(n,x) jointly generated with A209571; see the Formula section.

%C Combinatorial limit of row n satisfies linear recurrence

%C r(n)=4*r(n-1)-r(n-2) with r(1)=1 and r(2)=3. For a

%C 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)=2x*u(n-1,x)+x*v(n-1,x) +1,

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

%e First five rows:

%e 1

%e 1...3

%e 1...3...5

%e 1...3...11...7

%e 1...3...11...29...9

%e First three polynomials v(n,x): 1, 1 + 3x , 1 + 3x + 5x^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_] := 2 x*u[n - 1, x] + 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[%] (* A209571 *)

%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[%] (* A209572 *)

%Y Cf. A209571, A208510.

%K nonn,tabl

%O 1,3

%A _Clark Kimberling_, Mar 11 2012