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 A157748 Expansion of 1/(-x^11 + x^10 + 2*x^7 - x^6 - x^5 - x^4 - x^2 + 2*x + 1). 0
 1, -2, 5, -12, 30, -73, 180, -444, 1095, -2699, 6653, -16399, 40421, -99632, 245580, -605324, 1492048, -3677712, 9065100, -22344336, 55075988, -135755408, 334620068, -824796535, 2033020102, -5011139791, 12351831632, -30445717146 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 REFERENCES J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. xxxiii. LINKS FORMULA G.f.: 1/(-x^11 + x^10 + 2*x^7 - x^6 - x^5 - x^4 - x^2 + 2*x + 1). MATHEMATICA f[x_] = -1 + x + 2*x^4 - x^5 - x^6 - x^7 - x^9 + 2*x^10 + x^11; g[x] = ExpandAll[x^11*f[1/x]]; a = Table[SeriesCoefficient[ Series[1/g[x], {x, 0, 50}], n], {n, 0, 50}] CROSSREFS Sequence in context: A291253 A101911 A052109 * A046170 A262320 A062423 Adjacent sequences:  A157745 A157746 A157747 * A157749 A157750 A157751 KEYWORD sign,easy AUTHOR Roger L. Bagula, Mar 05 2009 EXTENSIONS New name from Joerg Arndt, Mar 20 2013 STATUS approved

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Last modified August 12 23:19 EDT 2020. Contains 336440 sequences. (Running on oeis4.)