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A209138 Triangle of coefficients of polynomials v(n,x) jointly generated with A209137; see the Formula section. 5

%I #18 Jan 22 2020 03:35:41

%S 1,1,2,2,4,3,3,9,10,5,5,18,28,22,8,8,35,68,74,45,13,13,66,154,210,177,

%T 88,21,21,122,331,541,574,397,167,34,34,222,686,1302,1656,1446,850,

%U 310,55,55,399,1382,2982,4404,4614,3434,1758,566,89,89,710,2723

%N Triangle of coefficients of polynomials v(n,x) jointly generated with A209137; see the Formula section.

%C Every row begins and ends with a Fibonacci number (A000045).

%C u(n,1) = n-th row sum = 3^(n-1).

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

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

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

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

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

%F From _Philippe Deléham_, Apr 11 2012: (Start)

%F T(n,k) = A185081(n,k+1).

%F T(n,k) = T(n-1,k) + T(n-1,k-1) + T(n-2,k) + T(n-2,k-1) + T(n-2,k-2), T(1,0) = T(2,0) = 1, T(2,1) = 2 and T(n,k) = 0 if k < 0 or if k >= n. (End)

%e First five rows:

%e 1;

%e 1, 2;

%e 2, 4, 3;

%e 3, 9, 10, 5;

%e 5, 18, 28, 22, 8;

%e First three polynomials v(n,x): 1, 1 + 2x, 2 + 4x + 3x^2.

%e From _Philippe Deléham_, Apr 11 2012: (Start)

%e Triangle in A185081 begins:

%e 1;

%e 0, 1;

%e 0, 1, 2;

%e 0, 2, 4, 3;

%e 0, 3, 9, 10, 5;

%e 0, 5, 18, 28, 22, 8;

%e ... (End)

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

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

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

%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[%] (* A209137 *)

%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[%] (* A209138 *)

%Y Cf. A209137, A208510.

%K nonn,tabl

%O 1,3

%A _Clark Kimberling_, Mar 05 2012

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)