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Table of n, a(n) for n=6..30.
A. J. Guttmann, Indicators of solvability for lattice models, Discrete Math., 217 (2000), 167-189 (H_6 for square lattices of Section 6).
Sequence in context: A080422 A030055 A155636 * A218093 A132261 A142364
Adjacent sequences: A055899 A055900 A055901 * A055903 A055904 A055905
Christian G. Bower, Jun 13 2000