A208527 Triangle of coefficients of polynomials v(n,x) jointly generated with A208526; see the Formula section.
1, 1, 4, 1, 4, 10, 1, 4, 12, 28, 1, 4, 14, 40, 76, 1, 4, 16, 52, 124, 208, 1, 4, 18, 64, 176, 384, 568, 1, 4, 20, 76, 232, 592, 1168, 1552, 1, 4, 22, 88, 292, 832, 1936, 3520, 4240, 1, 4, 24, 100, 356, 1104, 2880, 6240, 10512, 11584, 1, 4, 26, 112, 424, 1408
Offset: 1
Examples
First five rows: 1 1...4 1...4...10 1...4...12...28 1...4...14...40...76 First five polynomials v(n,x): 1 1 + 4x 1 + 4x + 10x^2 1 + 4x + 12x^2 + 28x^3 1 + 4x + 14x^2 + 40x^3 + 76x^4
Crossrefs
Cf. A208526.
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.