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 A122434 Expansion of (1+x)^3/(1+x+x^2). 1
 1, 2, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Row sums of number triangle A122433. Binomial transform is A077859. LINKS Index entries for linear recurrences with constant coefficients, signature (-1,-1). FORMULA a(n) = 2*sqrt(3)*cos(2*pi*n/3+pi/6)/3+C(1,n)+C(0,n). a(n) = -A049347(n) if n>=2 . - R. J. Mathar, Feb 08 2008 MATHEMATICA CoefficientList[Series[(1+x)^3/(1+x+x^2), {x, 0, 70}], x] (* or *) PadRight[ {1, 2, 0}, 71, {-1, 1, 0}] (* Harvey P. Dale, Apr 25 2012 *) CROSSREFS Sequence in context: A091430 A260728 A065339 * A141571 A164067 A305490 Adjacent sequences:  A122431 A122432 A122433 * A122435 A122436 A122437 KEYWORD easy,sign AUTHOR Paul Barry, Sep 04 2006 STATUS approved

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Last modified July 21 04:40 EDT 2019. Contains 325189 sequences. (Running on oeis4.)