%I M1144 #19 Jan 08 2019 05:15:55
%S 1,0,-1,-2,-4,-8,-17,-38,-88,-210,-511,-1264,-3165,-8006,-20426,
%T -52472,-135682,-352562,-920924,-2414272,-6356565,-16782444,-44470757,
%U -118090648,-314580062,-839379548,-2245969278,-6017177104,-16161597987
%N Percolation series for directed square lattice.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H I. Jensen, <a href="/A006461/b006461.txt">Table of n, a(n) for n = 0..54</a> (from link below)
%H R. J. Baxter and A. J. Guttmann, <a href="https://doi.org/10.1088/0305-4470/21/15/008">Series expansion of the percolation probability for the directed square lattice</a>, J. Phys. A 21 (1988), 3193-3204.
%H J. Blease, <a href="http://dx.doi.org/10.1088/0022-3719/10/7/003">Series expansions for the directed-bond percolation problem</a>, J. Phys C vol 10 no 7 (1977), 917-924.
%H I. G. Enting, A, J. Guttmann and I. Jensen, <a href="https://arxiv.org/abs/hep-lat/9410005">Low-Temperature Series Expansions for the Spin-1 Ising Model</a>, arXiv:hep-lat/9410005, 1994; J. Phys. A. 27 (1994) 6987-7006.
%H I. Jensen, <a href="https://web.archive.org/web/20070613022856/http://www.ms.unimelb.edu.au/~iwan/dirperc/series/sqbpp.ser">More terms</a> [Archived website]
%H Iwan Jensen, Anthony J. Guttmann, <a href="http://arxiv.org/abs/cond-mat/9509121">Series expansions of the percolation probability for directed square and honeycomb lattices</a>, arXiv:cond-mat/9509121, 1995; J. Phys. A 28 (1995), no. 17, 4813-4833.
%Y Cf. A006462.
%K sign,nice
%O 0,4
%A _N. J. A. Sloane_, _Simon Plouffe_