%I M1837 #17 Oct 04 2019 07:40:10
%S 0,2,8,22,52,112,228,442,832,1516,2720,4754,8264,14000,23824,39318,
%T 66052,106282,177884,277936,469384,703924,1225052,1718226,3203156,
%U 3974696,8551248,8307370,23950704,13195606,72779892,-1798186,246605280,-165440790,935635244,-1166043794,3896720688,-6470965954,17297466660,-33101156302,79718300900,-163586078926
%N Series for first parallel moment of 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="/A006732/b006732.txt">Table of n, a(n) for n = 0..158</a> (from link below)
%H J. W. Essam, A. J. Guttmann and K. De'Bell, <a href="https://doi.org/10.1088/0305-4470/21/19/018">On two-dimensional directed percolation</a>, J. Phys. A 21 (1988), 3815-3832.
%H I. Jensen, <a href="https://researchers.ms.unimelb.edu.au/~ij@unimelb/dirperc/series/sqst1.ser">More terms</a>
%H Iwan Jensen, Anthony J. Guttmann, <a href="https://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.
%K sign
%O 0,2
%A _N. J. A. Sloane_, _Simon Plouffe_