%I M0884 #42 Dec 17 2021 11:29:32
%S 1,1,2,3,8,23,3,1,1,2,100,1,20,1,63,1,29,2551
%N 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.
%D David C. Fisher, On the N X N Knight Cover Problem, Ars Combinatoria 69 (2003), 255-274.
%D M. Gardner, Mathematical Magic Show. Random House, NY, 1978, p. 194.
%D Bernard Lemaire, Knights Covers on N X N Chessboards, J. Recreational Mathematics, Vol. 31-2, 2003, 87-99.
%D Frank Rubin, Improved knight coverings, Ars Combinatoria 69 (2003), 185-196.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H Lee Morgenstern, <a href="https://web.archive.org/web/20070102070601/http://home.earthlink.net/~morgenstern/">Knight Domination</a>.
%H Frank Rubin, <a href="http://www.contestcen.com/knight.htm">Knight coverings for large chessboards</a>, 2000.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/KnightsProblem.html">Knights Problem</a>.
%Y Cf. A006075 (number of solutions), A098604 (rectangular board). A103315 gives the total number of solutions.
%K nonn,hard,nice
%O 1,3
%A _N. J. A. Sloane_
%E a(11) was found in 1973 by Bernard Lemaire. (_Philippe Deléham_, Jan 06 2004)
%E a(13)-a(17) from the Morgenstern web site, Nov 08 2004
%E a(18) from the Morgenstern web site, Mar 20 2005