A207627 Triangle of coefficients of polynomials u(n,x) jointly generated with A207628; see the Formula section.
1, 2, 3, 4, 4, 10, 8, 5, 18, 28, 16, 6, 28, 64, 72, 32, 7, 40, 120, 200, 176, 64, 8, 54, 200, 440, 576, 416, 128, 9, 70, 308, 840, 1456, 1568, 960, 256, 10, 88, 448, 1456, 3136, 4480, 4096, 2176, 512, 11, 108, 624, 2352, 6048, 10752, 13056, 10368, 4864
Offset: 1
Examples
First five rows: 1 2 3...4 4...10...8 5...18...28...16
Crossrefs
Cf. A207628.
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := u[n - 1, x] + v[n - 1, x] v[n_, x_] := 2 x*u[n - 1, x] + (x + 1)*v[n - 1, x] + 1 Table[Factor[u[n, x]], {n, 1, z}] Table[Factor[v[n, x]], {n, 1, z}] cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; TableForm[cu] Flatten[%] (* A207625 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A207626 *)
Formula
u(n,x)=u(n-1,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.
The row sums =: 2, 7, 22, 67, ... are given by (5*3^n -1)/2 for n = 0, 1, 2, 3, ... . - Philippe Deléham, Feb 25 2012
Comments