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A208906 Triangle of coefficients of polynomials v(n,x) jointly generated with A208905; see the Formula section. 3
1, 2, 1, 3, 2, 2, 4, 3, 8, 2, 5, 4, 20, 8, 4, 6, 5, 40, 20, 24, 4, 7, 6, 70, 40, 84, 24, 8, 8, 7, 112, 70, 224, 84, 64, 8, 9, 8, 168, 112, 504, 224, 288, 64, 16, 10, 9, 240, 168, 1008, 504, 960, 288, 160, 16, 11, 10, 330, 240, 1848, 1008, 2640, 960, 880, 160, 32 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
For a discussion and guide to related arrays, see A208510.
LINKS
FORMULA
u(n,x)=u(n-1,x)+2x*v(n-1,x),
v(n,x)=x*u(n-1,x)+v(n-1,x)+1,
where u(1,x)=1, v(1,x)=1.
EXAMPLE
First five rows:
1
2...1
3...2...2
4...3...8....2
5...4...20...8...4
First five polynomials v(n,x):
1
2 + x
3 + 2x + 2x^2
4 + 3x + 8x^2 + 2x^3
5 + 4x + 20x^2 + 8x^3 + 4x^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] + 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[%] (* A208905 *)
Table[Expand[v[n, x]], {n, 1, z}]
cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
TableForm[cv]
Flatten[%] (* A208906 *)
CROSSREFS
Sequence in context: A137948 A210553 A269456 * A120933 A209756 A210795
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Mar 03 2012
STATUS
approved

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Last modified July 23 23:47 EDT 2024. Contains 374575 sequences. (Running on oeis4.)