A207617 Triangle of coefficients of polynomials v(n,x) jointly generated with A207616; see the Formula section.
1, 2, 1, 3, 3, 4, 7, 1, 5, 14, 5, 6, 25, 16, 1, 7, 41, 41, 7, 8, 63, 91, 29, 1, 9, 92, 182, 92, 9, 10, 129, 336, 246, 46, 1, 11, 175, 582, 582, 175, 11, 12, 231, 957, 1254, 550, 67, 1, 13, 298, 1507, 2508, 1507, 298, 13, 14, 377, 2288, 4719, 3718, 1079, 92, 1
Offset: 1
Examples
First five rows: 1 2...1 3...3 4...7...1 5...14...5
Crossrefs
Cf. A207616.
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_] := x*u[n - 1, x] + 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[%] (* A207616 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A207617 *)
Formula
u(n,x)=u(n-1,x)+v(n-1,x), v(n,x)=xu(n-1,x)+v(n-1,x)+1, where u(1,x)=1, v(1,x)=1.