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A208911
Triangle of coefficients of polynomials u(n,x) jointly generated with A208912; see the Formula section.
3
1, 1, 2, 1, 6, 4, 1, 12, 14, 8, 1, 20, 32, 38, 16, 1, 30, 60, 110, 90, 32, 1, 42, 100, 250, 300, 214, 64, 1, 56, 154, 490, 770, 826, 490, 128, 1, 72, 224, 868, 1680, 2408, 2128, 1110, 256, 1, 90, 312, 1428, 3276, 5880, 6888, 5382, 2474, 512, 1, 110, 420
OFFSET
1,3
COMMENTS
For a discussion and guide to related arrays, see A208510.
FORMULA
u(n,x)=u(n-1,x)+2x*v(n-1,x),
v(n,x)=x*u(n-1,x)+(x+1)*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
EXAMPLE
First five rows:
1
1...2
1...6....4
1...12...14...8
1...20...32...38...16
First five polynomials u(n,x):
1
1 + 2x
1 + 6x + 4x^2
1 + 12x + 14x^2 + 8x^3
1 + 20x + 32x^2 + 38x^3 + 16x^4
MATHEMATICA
u[1, x_] := 1; v[1, x_] := 1; z = 16;
u[n_, x_] := u[n - 1, x] + 2 x*v[n - 1, x];
v[n_, x_] := x*u[n - 1, x] + (x + 1)*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[%] (* A208911 *)
Table[Expand[v[n, x]], {n, 1, z}]
cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
TableForm[cv]
Flatten[%] (* A208912 *)
CROSSREFS
Sequence in context: A208923 A185045 A208913 * A208761 A123519 A167024
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Mar 03 2012
STATUS
approved