A051570 Consider the problem of placing N queens on an n X n board so that each queen attacks precisely k others. Here k=3 and sequence gives number of different solutions when N takes its maximal value.

2, 4, 31, 307, 2, 9, 755, 39302

Offset: 3

Author

N. J. A. Sloane

Keywords

• nonn
• nice
• more

Comments

I would also like to get the sequences that gives the maximal values of N.

References

• M. Gardner, The Last Recreations, Springer, 1997, p. 282.

Crossrefs

Cf. A051567-A051571, A051754-A051759, A019654.

Extensions

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