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Table of n, a(n) for n=1..33.
Hang Gu and Robert M. Ziff, Crossing on hyperbolic lattices, arXiv preprint arXiv:1111.5626, 2011
Index entries for linear recurrences with constant coefficients, signature (4,-4,1).
G.f.: -7*x*(1+x) / ( (x-1)*(x^2-3*x+1) ). - R. J. Mathar, Nov 15 2013
Equals 7*A004146 for n >= 1.
Sequence in context: A037092 A210368 A015667 * A124090 A250284 A059595
Adjacent sequences: A206720 A206721 A206722 * A206724 A206725 A206726
N. J. A. Sloane, Feb 11 2012