A208611 Triangle of coefficients of polynomials v(n,x) jointly generated with A208610; see the Formula section.
1, 2, 3, 2, 6, 7, 2, 8, 18, 17, 2, 10, 30, 52, 41, 2, 12, 44, 102, 146, 99, 2, 14, 60, 170, 328, 402, 239, 2, 16, 78, 258, 610, 1014, 1090, 577, 2, 18, 98, 368, 1016, 2076, 3044, 2920, 1393, 2, 20, 120, 502, 1572, 3756, 6792, 8932, 7746, 3363, 2, 22, 144
Offset: 1
Examples
First five rows: 1 2...3 2...6....7 2...8....18...17 2...10...30...52...41 First five polynomials v(n,x): 1 2 + 3x 2 + 6x + 7x^2 2 + 8x + 18x^2 + 17x^3 2 + 10x + 30x^2 + 52x^3 + 41x^4
Crossrefs
Cf. A208610.
Programs
-
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_] := (x + 1)*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[%] (* A208610 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A208611 *)
Formula
u(n,x)=u(n-1,x)+x*v(n-1,x),
v(n,x)=(x+1)*u(n-1,x)+2x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.