A265061 Coordination sequence for (2,4,6) tiling of hyperbolic plane.

1, 3, 5, 8, 12, 17, 24, 33, 45, 61, 83, 114, 155, 210, 286, 389, 529, 720, 979, 1331, 1810, 2462, 3349, 4554, 6193, 8423, 11455, 15579, 21188, 28815, 39188, 53296, 72483, 98577, 134064, 182327, 247965, 337232, 458636, 623745, 848292, 1153677, 1569001, 2133841, 2902023, 3946750, 5367579, 7299906, 9927870, 13501901

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.

Index entries for linear recurrences with constant coefficients, signature (1, -1, 2, -1, 2, -1, 1, -1).

Formula

G.f.: (x+1)^2*(x^2+1)*(x^4+x^2+1)/(x^8-x^7+x^6-2*x^5+x^4-2*x^3+x^2-x+1).

Mathematica

CoefficientList[Series[(x + 1)^2 (x^2 + 1) (x^4 + x^2 + 1)/(x^8 - x^7 + x^6 - 2 x^5 + x^4 - 2 x^3 + x^2 - x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)

Prog

(PARI) Vec((x+1)^2*(x^2+1)*(x^4+x^2+1)/(x^8-x^7+x^6-2*x^5+x^4-2*x^3+x^2-x+1) + O(x^100)) \\ Altug Alkan, Dec 29 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: A038088 A018917 A167385 * A265062 A265063 A098202

Adjacent sequences: A265058 A265059 A265060 * A265062 A265063 A265064

Keyword

nonn,easy

Author

N. J. A. Sloane, Dec 29 2015

Status

approved