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.
LINKS
FORMULA
a(16) = A000170(16), the number of solutions.
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Peter Luschny, Sep 15 2018
STATUS
approved