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 A167373 Expansion of (1+x)*(3*x+1)/(1+x+x^2). 0
 1, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1, -2, 3, -1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Bisection of A138034. Also row 2n of A137276 or A135929. REFERENCES M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972, Chapter 22. LINKS Index entries for linear recurrences with constant coefficients, signature (-1,-1). FORMULA G.f.: (1+x)*(3*x+1)/(1+x+x^2). a(n) = a(n-3), n>4. a(n) = - a(n-1) - a(n-2) for n>2. a(n) = 4*sin(2*n*Pi/3)/sqrt(3)-2*cos(2*n*Pi/3) for n>0 with a(0)=1. - Wesley Ivan Hurt, Jun 12 2016 MATHEMATICA CoefficientList[Series[(1 + x)*(3*x + 1)/(1 + x + x^2), {x, 0, 50}], x] (* G. C. Greubel, Jun 12 2016 *) CROSSREFS Cf. A135929, A138034, A137276. Sequence in context: A195588 A153510 A288537 * A079722 A079723 A080511 Adjacent sequences:  A167370 A167371 A167372 * A167374 A167375 A167376 KEYWORD sign,easy AUTHOR Jamel Ghanouchi, Nov 02 2009 EXTENSIONS Edited by R. J. Mathar, Nov 03 2009 Further edited and extended by Simon Plouffe, Nov 23 2009 Recomputed by N. J. A. Sloane, Dec 20 2009 STATUS approved

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