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 A006736 Series for first parallel moment of hexagonal lattice. (Formerly M3597) 4
 0, 4, 24, 104, 384, 1284, 4012, 11924, 34100, 94584, 255852, 677850, 1764482, 4523924, 11447870, 28636218, 70907326, 173991368, 423469988, 1023162920, 2455645268, 5858183260, 13898041838, 32804047708, 77067740230 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The hexagonal lattice is the familiar 2-dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice. REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS I. Jensen, Table of n, a(n) for n = 0..90 (from link below) J. W. Essam, A. J. Guttmann and K. De'Bell, On two-dimensional directed percolation, J. Phys. A 21 (1988), 3815-3832. I. Jensen, More terms Iwan Jensen, Anthony J. Guttmann, Series expansions of the percolation probability for directed square and honeycomb lattices, arXiv:cond-mat/9509121, 1995; J. Phys. A 28 (1995), no. 17, 4813-4833. G. Nebe and N. J. A. Sloane, Home page for hexagonal (or triangular) lattice A2 CROSSREFS Cf. A006803, A006809, A006737. Sequence in context: A048806 A043009 A355798 * A165752 A166036 A120908 Adjacent sequences: A006733 A006734 A006735 * A006737 A006738 A006739 KEYWORD nonn AUTHOR STATUS approved

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Last modified December 8 19:12 EST 2022. Contains 358698 sequences. (Running on oeis4.)