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A141843
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Triangular array T(n,k) (n >= 1, 1 <= k <= n) read by rows: row n gives the lexicographically first solution to the n queens problem, or n zeroes if no solution exists. The k-th queen is placed in square (k, T(n, k)).
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2
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1, 0, 0, 0, 0, 0, 2, 4, 1, 3, 1, 3, 5, 2, 4, 2, 4, 6, 1, 3, 5, 1, 3, 5, 7, 2, 4, 6, 1, 5, 8, 6, 3, 7, 2, 4, 1, 3, 6, 8, 2, 4, 9, 7, 5, 1, 3, 6, 8, 10, 5, 9, 2, 4, 7, 1, 3, 5, 7, 9, 11, 2, 4, 6, 8, 10, 1, 3, 5, 8, 10, 12, 6, 11, 2, 7, 9, 4, 1, 3, 5, 2, 9, 12, 10
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,7
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COMMENTS
| Two further puzzle solutions were added to this sequence in November 2011; for board size 46x46 (a new solution) and for board size 47x47. The new puzzle solution for the 46x46 board was independently discovered by Matthias R. Engelhardt on 30th April 2011. The solution for the 47x47 board was discovered by Colin S. Pearson on 9th January 2008, but 47x47 can now be included in this sequence because the new 46x46 solution makes 47x47 contiguous with all previous solutions herein. The main contributer for this sequence can be contacted via a 'feedback' form at http://queens.cspea.co.uk/
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LINKS
| Colin S. Pearson, Table of n, a(n) for n = 1..1128
Matthias R. Engelhardt, The old nQueens problem
Colin S. Pearson, CSP Queens - Counting Queen-placements
Martin S. Pearson, Queens On A Chessboard
Wikipedia, Eight Queens Puzzle
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CROSSREFS
| Cf. A140450, A000170.
Sequence in context: A050980 A053451 A190555 * A130266 A198578 A173658
Adjacent sequences: A141840 A141841 A141842 * A141844 A141845 A141846
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KEYWORD
| nonn,tabl
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AUTHOR
| Colin S. Pearson (awayon[AT]cspea.co.uk)
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EXTENSIONS
| We extended this sequence by adding new terms 1036 to 1128 relating to two further puzzle solutions; for board size 46x46 (a new solution) and for board size 47x47. Given that the kth queen is placed in square (k, a(n, k)), we have added the terms (1, a(46, 1)) to (47, a(47, 47))
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