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 A265057 Coordination sequence for (2,3,7) tiling of hyperbolic plane. 27
 1, 3, 5, 7, 9, 12, 16, 20, 24, 28, 33, 40, 48, 57, 67, 78, 92, 109, 129, 152, 178, 209, 246, 290, 342, 402, 472, 555, 653, 769, 905, 1064, 1251, 1471, 1731, 2037, 2396, 2818, 3314, 3898, 4586, 5395, 6346, 7464, 8779, 10327, 12148, 14290, 16809, 19771, 23256, 27356, 32179, 37852, 44524, 52372 (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^6+x^5+x^4+x^3+x^2+x+1)*(x^2+x+1)*(x+1)^2/(x^10+x^9-x^7-x^6-x^5-x^4-x^3+x+1). MATHEMATICA CoefficientList[Series[(x^6 + x^5 + x^4 + x^3 + x^2 + x + 1) (x^2 + x + 1) (x + 1)^2/(x^10 + x^9 - x^7 - x^6 - x^5 - x^4 - x^3 + x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *) PROG (PARI) x='x+O('x^50); Vec((x^6+x^5+x^4+x^3+x^2+x+1)*(x^2+x+1)*(x+1)^2/(x^10+x^9-x^7-x^6-x^5-x^4-x^3+x+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: A226331 A316312 A118015 * A122643 A194240 A265058 Adjacent sequences:  A265054 A265055 A265056 * A265058 A265059 A265060 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Dec 29 2015 STATUS approved

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Last modified December 10 05:49 EST 2018. Contains 318044 sequences. (Running on oeis4.)