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 A001071 Number of one-sided chessboard polyominoes with n cells. (Formerly M0173 N0067) 2
 2, 1, 4, 10, 36, 108, 392, 1363, 5000, 18223, 67792, 252938, 952540, 3602478, 13699554, 52296713, 200406388, 770411478, 2970401696, 11482395526, 44491881090, 172766311857, 672186650116 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Two polyominoes cut from a chessboard are considered the same for this sequence if the shapes of the polyominoes are related by a rotation or translation, and the colorings are related by any symmetry including a reflection. - Joseph Myers, Oct 01 2011 REFERENCES W. F. Lunnon, personal communication. N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Joseph Myers, Chessboard polyominoes FORMULA a(n) = 2*O(n) - M(n) - 2*(R90(n) + R180(n)), where: O(n)=A000988(n), for even n, M(n)  = A234006(n/2), otherwise 0, for n multiple of 4, R90(n) = A234007(n/4), otherwise 0, for even n, R180(n) = A234008(n/2), otherwise 0 CROSSREFS Cf. A001933, A121198. Sequence in context: A134654 A198262 A085421 * A121198 A234599 A016544 Adjacent sequences:  A001068 A001069 A001070 * A001072 A001073 A001074 KEYWORD hard,nonn,more AUTHOR EXTENSIONS Extended by Joseph Myers, Oct 01 2011 a(18)-a(23) by John Mason, Jan 02 2014 STATUS approved

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Last modified January 20 11:11 EST 2020. Contains 331083 sequences. (Running on oeis4.)