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A209771
Triangle of coefficients of polynomials u(n,x) jointly generated with A209772; see the Formula section.
3
1, 1, 2, 2, 5, 4, 2, 9, 14, 8, 3, 14, 32, 36, 16, 3, 20, 60, 100, 88, 32, 4, 27, 100, 220, 288, 208, 64, 4, 35, 154, 420, 728, 784, 480, 128, 5, 44, 224, 728, 1568, 2240, 2048, 1088, 256, 5, 54, 312, 1176, 3024, 5376, 6528, 5184, 2432, 512, 6, 65, 420
OFFSET
1,3
COMMENTS
For a discussion and guide to related arrays, see A208510.
FORMULA
u(n,x)=x*u(n-1,x)+(x+1)*v(n-1,x),
v(n,x)=(x+1)*u(n-1,x)+x*v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
EXAMPLE
First five rows:
1
1...2
2...5....4
2...9....14...8
3...14...32...36...16
First three polynomials u(n,x): 1, 1 + 2x, 2 + 5x + 4x^2.
MATHEMATICA
u[1, x_] := 1; v[1, x_] := 1; z = 16;
u[n_, x_] := x*u[n - 1, x] + (x + 1)*v[n - 1, x];
v[n_, x_] := (x + 1)*u[n - 1, x] + 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[%] (* A209771 *)
Table[Expand[v[n, x]], {n, 1, z}]
cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
TableForm[cv]
Flatten[%] (* A209772 *)
CROSSREFS
Sequence in context: A135281 A068465 A217876 * A209751 A275381 A283235
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Mar 15 2012
STATUS
approved