OFFSET
1,1
LINKS
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).
FORMULA
G.f.: -7*x*(1+x) / ( (x-1)*(x^2-3*x+1) ). - R. J. Mathar, Nov 15 2013
MATHEMATICA
LinearRecurrence[{4, -4, 1}, {7, 35, 112}, 33] (* Jean-François Alcover, Sep 21 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Feb 11 2012
STATUS
approved