

A019654


Consider problem of placing N queens on an n X n board so that each queen attacks precisely k others. Here k=4 and sequence gives number of different solutions when N takes its maximal value.


11




OFFSET

3,5


COMMENTS

I would also like to get the sequences that give the maximal value of N.
An answer to this comment: I would also like to get the sequences that give the maximal value of N. What is the maximum number of queens that can be placed on an n*n chesboard such that no two attack one another? The answer is n queens, which gives eight queens for the usual 8*8 board (Madachy 1979; Steinhaus 1999, p. 29). The number of different ways the n queens can be placed on an n*n chessboard so that no two queens may attack each other for the first few n are 1, 0, 0, 2, 10, 4, 40, 92, ... [From Claudio (lordofchaos000(AT)hotmail.com), May 31 2010]


REFERENCES

M. Gardner, The Colossal Book of Mathematics, 2001, p. 209.
http://mathworld.wolfram.com/QueensProblem.html [From Claudio (lordofchaos000(AT)hotmail.com), May 31 2010]


LINKS

Table of n, a(n) for n=3..10.


CROSSREFS

Cf. A051567A051571, A051754A051759.
Sequence in context: A215196 A093376 A051571 * A156356 A143640 A047799
Adjacent sequences: A019651 A019652 A019653 * A019655 A019656 A019657


KEYWORD

nonn,nice,more


AUTHOR

N. J. A. Sloane, Oct 03, 2002


EXTENSIONS

I am not certain this description is correct, nor how rigorous the results are.


STATUS

approved



