%I M2207 #7 Mar 30 2012 16:45:04
%S 0,1,0,3,1,0,21,-34,101,-249,921,-2524,5613,-8914,6206
%N Percolation series for directed cubic lattice.
%D K. De'Bell and J. W. Essam, Estimates of the site percolation probability exponents for some directed lattices, J. Phys. A 16 (1983), 3145-3147.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%K sign
%O 2,4
%A _N. J. A. Sloane_.