

A006076


Sequence A006075 gives minimal number of knights needed to cover an n X n board. This sequence gives number of inequivalent solutions using A006075(n) knights.
(Formerly M0884)


6



1, 1, 2, 3, 8, 23, 3, 1, 1, 2, 100, 1, 20, 1, 63, 1, 29, 2551
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OFFSET

1,3


REFERENCES

David C. Fisher, On the N X N Knight Cover Problem, Ars Combinatoria 69 (2003), 255274.
M. Gardner, Mathematical Magic Show. Random House, NY, 1978, p. 194.
Bernard Lemaire, Knights Covers on N X N Chessboards, J. Recreational Mathematics, Vol. 312, 2003, 8799.
Frank Rubin, Improved knight coverings, Ars Combinatoria 69 (2003), 185196.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=1..18.
Lee Morgenstern, Knight Domination.
Frank Rubin, Knight coverings for large chessboards, 2000.
Eric Weisstein's World of Mathematics, Knights Problem.


CROSSREFS

Cf. A006075 (number of solutions), A098604 (rectangular board). A103315 gives the total number of solutions.
Sequence in context: A127940 A006796 A241904 * A263459 A261061 A086628
Adjacent sequences: A006073 A006074 A006075 * A006077 A006078 A006079


KEYWORD

nonn,hard,nice


AUTHOR

N. J. A. Sloane.


EXTENSIONS

a(11) was found in 1973 by Bernard Lemaire. (Philippe Deléham, Jan 06 2004)
a(13)a(17) from the Morgenstern web site, Nov 08 2004
a(18) from the Morgenstern web site, Mar 20 2005


STATUS

approved



