A209171 Triangle of coefficients of polynomials v(n,x) jointly generated with A209170; see the Formula section.
1, 3, 2, 6, 8, 3, 12, 25, 19, 5, 24, 68, 77, 40, 8, 48, 172, 259, 201, 80, 13, 96, 416, 782, 806, 478, 154, 21, 192, 976, 2200, 2825, 2222, 1067, 289, 34, 384, 2240, 5888, 9048, 8857, 5640, 2277, 532, 55, 768, 5056, 15184, 27160, 31787, 25184, 13483
Offset: 1
Examples
First five rows: 1; 3, 2; 6, 8, 3; 12, 25, 19, 5; 24, 68, 77, 40, 8; First three polynomials v(n,x): 1 3 + 2x 6 + 8x + 3x^2. From _Philippe Deléham_, Mar 10 2012: (Start) Triangle (1, 2, -3/2, 1/2, 0, 0, ...) DELTA (0, 2, -1/2, -1/2, 0, 0, ...) begins (0 <= k <= n): 1; 1, 0; 3, 2, 0; 6, 8, 3, 0; 12, 25, 19, 5, 0; 24, 68, 77, 40, 8, 0; 48, 172, 259, 201, 80, 13, 0; 96, 416, 782, 806, 478, 154, 21, 0; (End)
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x]; v[n_, x_] := (x + 1)*u[n - 1, x] + (x + 1)*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[%] (* A209170 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209171 *)
Formula
u(n,x) = u(n-1,x) + (x+1)*v(n-1,x),
v(n,x) = (x+1)*u(n-1,x) + (x+1)*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
T(n,k) = 2*T(n-1,k) + T(n-1,k-1) + T(n-2,k-1) + T(n-2,k-2), T(1,0) = 1, T(2,0) = 3, T(2,1) = 2. - Philippe Deléham, Mar 10 2012
Sum_{k=0..n} T(n,k)*x^k = A000012(n), A003945(n-1), A007483(n-1) for x = -1, 0, 1 respectively. - Philippe Deléham, Mar 10 2012
G.f.: (-1-x-x*y)*x*y/(-1+2*x+x*y+x^2*y^2+x^2*y). - R. J. Mathar, Aug 12 2015
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