A187047 Number of 3-step one or two space at a time bishop's tours on an n X n board summed over all starting positions.

0, 0, 28, 136, 360, 696, 1144, 1704, 2376, 3160, 4056, 5064, 6184, 7416, 8760, 10216, 11784, 13464, 15256, 17160, 19176, 21304, 23544, 25896, 28360, 30936, 33624, 36424, 39336, 42360, 45496, 48744, 52104, 55576, 59160

Offset: 1

Author

R. H. Hardin Mar 02 2011

Keywords

• nonn

Comments

Row 3 of A187046

Examples

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

Formula

Empirical: a(n) = 56*n^2 - 280*n + 360 for n>3