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A265068 Coordination sequence for (2,5,infinity) tiling of hyperbolic plane. 27
1, 3, 5, 8, 13, 20, 30, 46, 71, 109, 167, 256, 393, 603, 925, 1419, 2177, 3340, 5124, 7861, 12060, 18502, 28385, 43547, 66808, 102494, 157242, 241234, 370091, 567778, 871061, 1336345, 2050164, 3145275, 4825348, 7402845, 11357132, 17423632, 26730600, 41008957, 62914209, 96520321, 148077398, 227174087, 348520885 (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^4+x^3+x^2+x+1)*(x+1)^2/(x^5+x^4+x^3+x^2-1).

MATHEMATICA

CoefficientList[Series[-(x^4 + x^3 + x^2 + x + 1) (x + 1)^2/(x^5 + x^4 + x^3 + x^2 - 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)

PROG

(PARI) Vec(-(x^4+x^3+x^2+x+1)*(x+1)^2/(x^5+x^4+x^3+x^2-1) + O(x^50)) \\ Michel Marcus, Dec 30 2015

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: A265065 A265066 A265067 * A227547 A163685 A080614

Adjacent sequences:  A265065 A265066 A265067 * A265069 A265070 A265071

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Dec 29 2015

STATUS

approved

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Last modified November 17 07:44 EST 2018. Contains 317275 sequences. (Running on oeis4.)