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Search: id:A132443
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| A132443 |
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Number of n x n crossword puzzles with rotational symmetry and exactly one black square per row. |
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+0
4
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OFFSET
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3,4
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COMMENT
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Acceptable crossword puzzles must have all words of length 3 or more, at least one word in each row and each column and be connected.
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LINKS
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Marc Brodie, Mathematica program
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EXAMPLE
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a(6) = 2 because the only two 6 X 6 crossword puzzles are (using 1's for black squares and 0's for white):
100000
100000
100000
000001
000001
000001
and
000001
000001
000001
100000
100000
100000
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CROSSREFS
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Cf. A130578, A132444, A132445, A132446.
Sequence in context: A147801 A066965 A066966 this_sequence A048153 A015623 A164124
Adjacent sequences: A132440 A132441 A132442 this_sequence A132444 A132445 A132446
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KEYWORD
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nonn
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AUTHOR
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Marc Brodie (mbrodie(AT)wju.edu), Aug 21 2007
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