A209755 Triangle of coefficients of polynomials u(n,x) jointly generated with A209756; see the Formula section.
1, 1, 2, 2, 4, 3, 3, 7, 8, 5, 4, 11, 17, 17, 8, 5, 16, 31, 41, 33, 13, 6, 22, 51, 83, 91, 63, 21, 7, 29, 78, 150, 205, 195, 117, 34, 8, 37, 113, 250, 406, 483, 403, 214, 55, 9, 46, 157, 392, 734, 1039, 1091, 812, 386, 89, 10, 56, 211, 586, 1239, 2023, 2536
Offset: 1
Examples
First five rows: 1 1...2 2...4....3 3...7....8....5 4...11...11...17...8 First three polynomials u(n,x): 1, 1 + 2x, 2 + 4x + 3x^2.
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := x*u[n - 1, x] + (x + 1)*v[n - 1, x]; v[n_, x_] := x*u[n - 1, x] + 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[%] (* A209755 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A209756 *) Table[u[n, x] /. x -> 1, {n, 1, z}] (* A133654 *) Table[v[n, x] /. x -> 1, {n, 1, z}] (* A001333 *) Table[u[n, x] /. x -> -1, {n, 1, z}] (* A033999 *) Table[v[n, x] /. x -> -1, {n, 1, z}] (* A109613 *)
Formula
u(n,x)=x*u(n-1,x)+(x+1)*v(n-1,x),
v(n,x)=x*u(n-1,x)+v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
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