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 A265059 Coordination sequence for (2,3,9) tiling of hyperbolic plane. 27
 1, 3, 5, 7, 9, 12, 16, 21, 28, 36, 45, 56, 70, 89, 113, 143, 181, 228, 287, 361, 455, 575, 726, 916, 1155, 1456, 1836, 2315, 2920, 3684, 4647, 5861, 7391, 9321, 11756, 14827, 18701, 23587, 29749, 37520, 47320, 59681, 75272, 94936, 119737, 151016, 190466, 240221, 302973, 382119, 481941, 607840, 766627 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS G. C. Greubel, Table of n, a(n) for n = 0..1000 J. W. Cannon, P. Wagreich, Growth functions of surface groups, Mathematische Annalen, 1992, Volume 293, pp. 239-257. See Prop. 3.1. FORMULA G.f.: (x+1)^2*(x^2+x+1)*(x^6+x^3+1)/(x^10-x^8-x^5-x^2+1). MATHEMATICA CoefficientList[Series[(x + 1)^2 (x^2 + x + 1) (x^6 + x^3 + 1)/(x^10 - x^8 - x^5 - x^2 + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *) PROG (PARI) x='x+O('x^50); Vec((x+1)^2*(x^2+x+1)*(x^6+x^3+1)/(x^10-x^8-x^5-x^2+1)) \\ G. C. Greubel, Aug 06 2017 CROSSREFS Coordination sequences for triangular tilings of hyperbolic space: A001630, A007283, A054886, A078042, A096231, A163876, A179070, A265057, A265058, A265059, A265060, A265061, A265062, A265063, A265064, A265065, A265066, A265067, A265068, A265069, A265070, A265071, A265072, A265073, A265074, A265075, A265076, A265077. Sequence in context: A122643 A194240 A265058 * A096231 A100432 A261033 Adjacent sequences:  A265056 A265057 A265058 * A265060 A265061 A265062 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Dec 29 2015 STATUS approved

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Last modified November 15 11:35 EST 2018. Contains 317238 sequences. (Running on oeis4.)