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A265063
Coordination sequence for (2,4,8) tiling of hyperbolic plane.
27
1, 3, 5, 8, 12, 17, 25, 37, 53, 75, 107, 152, 216, 309, 441, 628, 895, 1275, 1816, 2588, 3689, 5257, 7491, 10675, 15211, 21675, 30888, 44016, 62723, 89381, 127368, 181499, 258637, 368560, 525200, 748413, 1066493, 1519757, 2165661, 3086079, 4397679, 6266716, 8930104, 12725445, 18133825, 25840796, 36823271, 52473355
OFFSET
0,2
LINKS
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^2+1)*(x^4+1)*(x+1)^2/(x^8-x^7-x^5+x^4-x^3-x+1).
MATHEMATICA
CoefficientList[Series[(x^2 + 1)*(x^4 + 1)*(x + 1)^2/(x^8 - x^7 - x^5 + x^4 - x^3 - x + 1), {x, 0, 50}], x] (* G. C. Greubel, Aug 07 2017 *)
LinearRecurrence[{1, 0, 1, -1, 1, 0, 1, -1}, {1, 3, 5, 8, 12, 17, 25, 37, 53}, 50] (* Harvey P. Dale, Jul 26 2024 *)
PROG
(PARI) Vec((x^2+1)*(x^4+1)*(x+1)^2/(x^8-x^7-x^5+x^4-x^3-x+1) + O(x^100)) \\ Altug Alkan, Dec 29 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 29 2015
STATUS
approved