A187028 Number of 3-step one or two collinear space at a time queen's tours on an n X n board summed over all starting positions

0, 24, 296, 1008, 2232, 3936, 6120, 8784, 11928, 15552, 19656, 24240, 29304, 34848, 40872, 47376, 54360, 61824, 69768, 78192, 87096, 96480, 106344, 116688, 127512, 138816, 150600, 162864, 175608

Offset

1,2

Comments

Row 3 of A187027

Links

Table of n, a(n) for n=1..29.

Formula

Empirical: a(n) = 240*n^2 - 936*n + 912 for n>3

Example

Some solutions for 4X4
..0..3..0..0....0..0..0..2....0..0..3..0....0..2..3..1....2..0..1..0
..0..2..0..0....0..0..3..0....0..0..2..1....0..0..0..0....0..0..0..0
..0..0..1..0....0..1..0..0....0..0..0..0....0..0..0..0....0..0..3..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0

Crossrefs

Sequence in context: A295272 A369469 A086941 * A186966 A281134 A128598

Adjacent sequences: A187025 A187026 A187027 * A187029 A187030 A187031

Keyword

nonn

Author

R. H. Hardin Mar 02 2011

Status

approved