A208526 Triangle of coefficients of polynomials u(n,x) jointly generated with A208527; see the Formula section.
1, 1, 1, 1, 2, 4, 1, 3, 8, 10, 1, 4, 12, 22, 28, 1, 5, 16, 36, 68, 76, 1, 6, 20, 52, 120, 200, 208, 1, 7, 24, 70, 184, 376, 592, 568, 1, 8, 28, 90, 260, 608, 1184, 1736, 1552, 1, 9, 32, 112, 348, 900, 2016, 3672, 5072, 4240, 1, 10, 36, 136, 448, 1256, 3120
Offset: 1
Examples
First five rows: 1 1...1 1...2...4 1...3...8....10 1...4...12...22...28 First five polynomials u(n,x): 1 1 + x 1 + 2x + 4x^2 1 + 3x + 8x^2 + 10x^3 1 + 4x + 12x^2 + 22x^3 + 28x^4
Crossrefs
Cf. A208527.
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := u[n - 1, x] + x*v[n - 1, x]; v[n_, x_] := 2 x*u[n - 1, x] + 2 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[%] (* A208526 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A208527 *)
Formula
u(n,x)=u(n-1,x)+x*v(n-1,x),
v(n,x)=2x*u(n-1,x)+2x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.