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A054421
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Number of disconnected 3 X n binary matrices.
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5
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0, 1, 11, 102, 882, 7295, 58533, 459484, 3547860, 27043405, 204016879, 1526141666, 11336059046, 83703379691, 614911337833, 4497505562616, 32769214114664, 237956784843737, 1722809101653651, 12440161483566494
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| A connected (0,1) matrix is one where you can get from any black square, i.e. 1, to any other by chess king moves.
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REFERENCES
| R. Levy and J. Shapiro, Uniqueness in paint-by-numbers puzzles, preprint, 2000.
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CROSSREFS
| Cf. A054417-A054420. 4*A054421(n) + 2*A054419(n) + A054420(n) = 7^n.
Sequence in context: A180280 A100580 A087744 * A037700 A037609 A055150
Adjacent sequences: A054418 A054419 A054420 * A054422 A054423 A054424
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), May 22 2000
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EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), May 23 2000
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