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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
M. F. Sykes and J. W. Essam, Critical percolation probabilities by series methods, Phys. Rev., 133 (1964), A310-A315.
Table of n, a(n) for n=0..7.
Sequence in context: A100312 A204643 * A036393 A196097 A234272 A269077
Adjacent sequences: A003198 A003199 A003200 * A003202 A003203 A003204
N. J. A. Sloane.