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A117907 Expansion of (1+x+x^2+x^3+x^4+x^5+x^6)/(1+x+x^2+x^3+x^4+x^5). 1
1, -1, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1, 0, 0, 0, 1, -2, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

Diagonal sums of number triangle A117906.

LINKS

Table of n, a(n) for n=0..62.

Index entries for linear recurrences with constant coefficients, signature (-1,-1,-1,-1,-1).

FORMULA

G.f.: x+(1-x)^2/(1-x^6)

MATHEMATICA

CoefficientList[Series[x+(1-x)^2/(1-x^6), {x, 0, 90}], x] (* or *) Join[{1, -1}, LinearRecurrence[{-1, -1, -1, -1, -1}, {1, 0, 0, 0, 1}, 90]] (* or *) PadRight[ {1, -1}, 90, {1, -2, 1, 0, 0, 0}] (* Harvey P. Dale, Nov 29 2013 *)

CROSSREFS

Sequence in context: A064662 A024944 A304871 * A300069 A284586 A281244

Adjacent sequences:  A117904 A117905 A117906 * A117908 A117909 A117910

KEYWORD

easy,sign

AUTHOR

Paul Barry, Apr 01 2006

STATUS

approved

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Last modified January 28 00:32 EST 2020. Contains 331313 sequences. (Running on oeis4.)