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 A319235 The profile of the backtrack tree for the eight queens problem. 1
 1, 8, 42, 140, 344, 568, 550, 312, 92 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The profile (p_0, p_1, ..., p_n) is the number of nodes at each level of the tree. The backtrack tree as defined by Knuth has for the eight queens problem 2057 nodes. REFERENCES D. E. Knuth, The Art of Computer Programming, Volume 4, Pre-fascicle 5B, Introduction to Backtracking, 7.2.2. Backtrack programming. 2018. LINKS Wikipedia, Backtracking Wikipedia, Eight queens puzzle FORMULA a(8) = A000170(8), the number of solutions. CROSSREFS Cf. A000170, A319236. Sequence in context: A292059 A027903 A231069 * A341764 A256861 A287221 Adjacent sequences:  A319232 A319233 A319234 * A319236 A319237 A319238 KEYWORD nonn,fini,full AUTHOR Peter Luschny, Sep 15 2018 STATUS approved

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Last modified December 6 11:48 EST 2021. Contains 349563 sequences. (Running on oeis4.)