A187293 Number of 8-step one or two space at a time rook's tours on an n X n board summed over all starting positions

0, 0, 2664, 134944, 866888, 2732016, 6049424, 10906120, 17282088, 25129488, 34417440, 45129696, 57260948, 70809512, 85775112, 102157696, 119957264, 139173816, 159807352, 181857872, 205325376, 230209864, 256511336, 284229792

Offset

1,3

Comments

Row 8 of A187286

Links

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

Formula

Empirical: a(n) = 708492*n^2 - 5580668*n + 10074432 for n>13

Example

Some solutions for 4X4
..0..5..1..0....0..5..6..0....5..4..6..3....0..0..0..6....3..2..0..1
..0..6..2..0....8..4..7..3....0..0..7..1....0..8..0..7....0..0..0..0
..0..4..3..0....0..0..0..2....0..0..8..2....0..3..4..5....4..0..0..8
..0..7..0..8....0..0..0..1....0..0..0..0....0..2..1..0....5..6..0..7

Crossrefs

Sequence in context: A224685 A167191 A002482 * A187195 A107532 A110838

Adjacent sequences: A187290 A187291 A187292 * A187294 A187295 A187296

Keyword

nonn

Author

R. H. Hardin Mar 08 2011

Status

approved