A187856 Number of 8-step king-knight's tours (piece capable of both kinds of moves) on an n X n board summed over all starting positions.

0, 0, 49536, 7067600, 71450504, 288493336, 741624088, 1474319716, 2497432760, 3806665836, 5395343360, 7259273932, 9396774760, 11807403172, 14491089616, 17447829164, 20677621816, 24180467572, 27956366432, 32005318396, 36327323464

Offset: 1

Author

R. H. Hardin Mar 14 2011

Keywords

• nonn

Comments

Row 8 of A187850

Examples

			Some solutions for 3X3
..8..5..2....0..8..4....5..4..3....8..4..6....0..4..7....8..4..5....8..4..1
..7..6..1....3..7..1....8..2..6....5..3..7....5..2..8....2..0..7....7..2..3
..4..3..0....6..5..2....0..1..7....0..1..2....1..6..3....1..6..3....5..6..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..50

Formula

Empirical: a(n) = 136526552*n^2 - 1275583564*n + 2906368876 for n>13