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A210555 Triangle of coefficients of polynomials u(n,x) jointly generated with A210556; see the Formula section. 2
1, 1, 2, 1, 3, 4, 1, 4, 7, 8, 1, 5, 10, 17, 16, 1, 6, 13, 28, 39, 32, 1, 7, 16, 41, 70, 89, 64, 1, 8, 19, 56, 109, 176, 199, 128, 1, 9, 22, 73, 156, 297, 426, 441, 256, 1, 10, 25, 92, 211, 456, 765, 1020, 967, 512, 1, 11, 28, 113, 274, 657, 1236, 1953, 2398 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

For a discussion and guide to related arrays, see A208510.

LINKS

Table of n, a(n) for n=1..64.

FORMULA

u(n,x)=x*u(n-1,x)+x*v(n-1,x)+1,

v(n,x)=2x*u(n-1,x)+v(n-1,x)+1,

where u(1,x)=1, v(1,x)=1.

EXAMPLE

First five rows:

1

1...2

1...3...4

1...4...7....8

1...5...10...17...16

First three polynomials u(n,x): 1, 1 + 2x, 1 + 3x + 4x^2.

MATHEMATICA

u[1, x_] := 1; v[1, x_] := 1; z = 16;

u[n_, x_] := x*u[n - 1, x] + x*v[n - 1, x] + 1;

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[%]   (* A208341 *)

Table[Expand[v[n, x]], {n, 1, z}]

cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];

TableForm[cv]

Flatten[%]   (* A210554 *)

CROSSREFS

Cf. A210554, A208510.

Sequence in context: A132110 A039912 A163311 * A008949 A076832 A078925

Adjacent sequences:  A210552 A210553 A210554 * A210556 A210557 A210558

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Mar 22 2012

STATUS

approved

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Last modified November 21 07:01 EST 2017. Contains 294989 sequences.