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A319236
The profile of the backtrack tree for the sixteen queens problem.
1
1, 16, 210, 2236, 19688, 141812, 838816, 3998456, 15324708, 46358876, 108478966, 193892860, 260303408, 253897632, 171158018, 72002088, 14772512
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 sixteen queens problem 1141190303 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(16) = A000170(16), the number of solutions.
CROSSREFS
Sequence in context: A283694 A283126 A295712 * A222447 A059385 A009440
KEYWORD
nonn,fini,full
AUTHOR
Peter Luschny, Sep 15 2018
STATUS
approved