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A265065 Coordination sequence for (2,5,6) tiling of hyperbolic plane. 27
1, 3, 5, 8, 13, 20, 29, 42, 62, 91, 132, 192, 281, 410, 597, 870, 1269, 1851, 2698, 3933, 5735, 8362, 12191, 17774, 25915, 37784, 55088, 80317, 117102, 170734, 248927, 362932, 529151, 771496, 1124831, 1639989, 2391084, 3486171, 5082793, 7410648, 10804633, 15753020, 22967705, 33486626, 48823082, 71183443, 103784568 (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^4+x^3+x^2+x+1)*(x^4+x^2+1)/(x^10-x^7-x^6-2*x^5-x^4-x^3+1).

MATHEMATICA

CoefficientList[Series[(x + 1)^2 (x^4 + x^3 + x^2 + x + 1) (x^4 + x^2 + 1) / (x^10 - x^7 - x^6 - 2 x^5 - x^4 - x^3 + 1), {x, 0, 45}], x] (* Vincenzo Librandi, Jan 20 2016 *)

PROG

(PARI) Vec((x+1)^2*(x^4+x^3+x^2+x+1)*(x^4+x^2+1)/(x^10-x^7-x^6-2*x^5-x^4-x^3+1) + O(x^50)) \\ Michel Marcus, Jan 20 2016

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: A035424 A245934 A099351 * A265066 A265067 A265068

Adjacent sequences:  A265062 A265063 A265064 * A265066 A265067 A265068

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 29 2015

STATUS

approved

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Last modified November 12 21:10 EST 2018. Contains 317116 sequences. (Running on oeis4.)