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

1,3

Comments

Row 8 of A187850

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

Example

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

Crossrefs

Sequence in context: A210351 A234563 A251881 * A258320 A258131 A081636

Adjacent sequences: A187853 A187854 A187855 * A187857 A187858 A187859

Keyword

nonn

Author

R. H. Hardin Mar 14 2011

Status

approved