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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
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.
FORMULA
a(8) = A000170(8), the number of solutions.
CROSSREFS
Sequence in context: A292059 A027903 A231069 * A341764 A256861 A287221
KEYWORD
nonn,fini,full
AUTHOR
Peter Luschny, Sep 15 2018
STATUS
approved