A260189 a(n) = A033148(n) / 2^floor(n/4).

1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 4, 8, 0, 0, 15, 22, 0, 0, 52, 51, 0, 0, 257, 342, 0, 0, 1589, 2609, 0, 0, 11417, 16896, 0, 0, 75375, 99114, 0, 0, 616010, 876579, 0, 0, 5253278, 8551800, 0, 0, 49667373, 79595269, 0, 0, 525731268, 764804085, 0, 0, 5932910966, 8905825760, 0, 0

Offset

1,16

References

W. Ahrens, Mathematische Unterhaltungen und Spiele, 2nd edition, volume 1, Teubner, 1910, pages 249-258.

Maurice Kraitchik, Le probleme des reines, Bruxelles: L'Échiquier, 1926, 18.

Links

Table of n, a(n) for n=1..63.

P. Capstick and K. McCann, The problem of the n queens, apparently unpublished, no date (circa 1990?) [Scanned copy]

Crossrefs

Cf. A002562, A032522, A033148, A037223, A037224.

Sequence in context: A028583 A305744 A182500 * A208926 A070263 A176912

Adjacent sequences: A260186 A260187 A260188 * A260190 A260191 A260192

Keyword

nonn,hard

Author

Vaclav Kotesovec, following a suggestion of Don Knuth, Jul 18 2015

Status

approved