A051571 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.

0, 0, 0, 1, 3, 40, 615, 16573

Offset: 3

Author

N. J. A. Sloane

Keywords

• nonn
• more

References

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

Crossrefs

Cf. A051567-A051570, A051754-A051759, A019654.

Extensions

Probably an incorrect version of A019654.