

A051754


Consider problem of placing N queens on an n X n board so that each queen attacks precisely 1 other. Sequence gives maximal number of queens.


12




OFFSET

2,1


COMMENTS

2*[2n/3] is an upper bound for a(n), which is achieved for n=2, 4 and 614.  Jud McCranie, Aug 12 2001


REFERENCES

Martin Gardner, The Last Recreations, Copernicus, NY, 1997, 274283.


LINKS

Table of n, a(n) for n=2..11.


CROSSREFS

Cf. A051755A051759, A051567A051571, A019654.
Sequence in context: A190172 A059867 A046971 * A108747 A116931 A206558
Adjacent sequences: A051751 A051752 A051753 * A051755 A051756 A051757


KEYWORD

nonn,nice


AUTHOR

Robert Trent (trentrd(AT)hotmail.com), Aug 23 2000


STATUS

approved



