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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
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
Sequence in context: A134654 A198262 A085421 * A121198 A234599 A016544
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 March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)