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A194001 Mirror of the triangle A194000. 3
1, 3, 2, 9, 5, 3, 24, 15, 8, 5, 64, 39, 24, 13, 8, 168, 104, 63, 39, 21, 13, 441, 272, 168, 102, 63, 34, 21, 1155, 714, 440, 272, 165, 102, 55, 34, 3025, 1869, 1155, 712, 440, 267, 165, 89, 55, 7920, 4895, 3024, 1869, 1152, 712, 432, 267, 144, 89, 20736 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

A194001 is obtained by reversing the rows of the triangle A194000.

Here, we extend of the conjecture begun at A194000.  Suppose n is an odd positive integer and r(n+1,x) is the polynomial matched to row n+1 of A194001 as in the Mathematica program, where the first row is counted as row 0.

Conjecture:  r(n+1,x) is the product of the following two polynomials whose coefficients are Fibonacci numbers:

linear factor:  F(n+2)+x*F(n+3)

  other: F(2)+F(4)*x^2+F(6)*x^4+...+F(n+1)*x^(n-1).

Example, for n=5:

  r(6,x)=168*x^5+104*x^4+63*x^3+39^x^2+21*x+13 factors as

  13+21x times 1+3x^2+8x^4.

LINKS

Table of n, a(n) for n=0..55.

FORMULA

Write w(n,k) for the triangle at A194000.  The triangle at A194001 is then given by w(n,n-k).

EXAMPLE

First six rows:

1

3....2

9....5....3

21...13...7....4

41...28...17...9....5

71...52...35...21...11...6

MATHEMATICA

z = 11;

p[n_, x_] := Sum[Fibonacci[k + 1]*x^(n - k), {k, 0, n}];

q[n_, x_] := p[n, x];

p1[n_, k_] := Coefficient[p[n, x], x^k];

p1[n_, 0] := p[n, x] /. x -> 0;

d[n_, x_] := Sum[p1[n, k]*q[n - 1 - k, x], {k, 0, n - 1}]

h[n_] := CoefficientList[d[n, x], {x}]

TableForm[Table[Reverse[h[n]], {n, 0, z}]]

Flatten[Table[Reverse[h[n]], {n, -1, z}]]  (* A194000 *)

TableForm[Table[h[n], {n, 0, z}]]

Flatten[Table[h[n], {n, -1, z}]]  (* A194001 *)

CROSSREFS

Cf. A194000, A193918.

Sequence in context: A090880 A188926 A193980 * A178230 A064614 A016650

Adjacent sequences:  A193998 A193999 A194000 * A194002 A194003 A194004

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Aug 11 2011

STATUS

approved

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Last modified May 21 20:36 EDT 2013. Contains 225504 sequences.