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A231148 Array of coefficients of numerator polynomials of the rational function p(n, x - 1/x), where p(n,x) = (x^n - 1)/(x - 1). 1
1, -1, 1, 1, 1, -1, -1, 1, 1, -1, 1, 2, -1, -2, 1, 1, 1, -1, -3, 2, 5, -2, -3, 1, 1, -1, 1, 4, -3, -8, 5, 8, -3, -4, 1, 1, 1, -1, -5, 4, 12, -8, -15, 8, 12, -4, -5, 1, 1, -1, 1, 6, -5, -17, 12, 27, -15, -27, 12, 17, -5, -6, 1, 1, 1, -1, -7, 6, 23, -17, -44 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,12

LINKS

Table of n, a(n) for n=1..71.

EXAMPLE

First 4 rows:

1

-1 1 1

1 -1 -1 1 1

-1 1 2 -1 -2 1 1

First 4 polynomials: 1, -1 + x + x^2, 1 - x - x^2 + x^3 + x^4

MATHEMATICA

z = 60; p[n_, x_] := p[x] = (x^n - 1)/(x - 1); Table[p[n, x], {n, 1, z/4}]; f1[n_, x_] := f1[n, x] = Numerator[Factor[p[n, x] /. x -> x - 1/x]]; Table[Expand[f1[n, x]], {n, 0, z/4}]

Flatten[Table[CoefficientList[f1[n, x], x], {n, 1, z/4}]]

CROSSREFS

Cf. A231147.

Sequence in context: A048138 A165022 A030338 * A266649 A159847 A257886

Adjacent sequences:  A231145 A231146 A231147 * A231149 A231150 A231151

KEYWORD

tabf,sign,easy

AUTHOR

Clark Kimberling, Nov 05 2013

STATUS

approved

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Last modified June 23 16:45 EDT 2017. Contains 288666 sequences.