A160392 Length of the longest directed, closed, non-intersecting rook path on an n X n chessboard avoiding right turns on squares of one color and avoiding left turns on the other color.

0, 0, 8, 12, 16, 20, 40, 48, 62, 76, 98, 116, 136, 156, 188, 208

Offset

1,3

Comments

Turns must be chromatically correct. E.g., n=3, R=Right Turn, A=Ahead, longest path is 8:

RAR

A A

RAR

Links

Table of n, a(n) for n=1..16.

Alex Chernov, Length of the longest rook path

Crossrefs

Sequence in context: A337806 A192544 A302139 * A242272 A078609 A084809

Adjacent sequences: A160389 A160390 A160391 * A160393 A160394 A160395

Keyword

hard,nonn

Author

David Scambler, May 12 2009

Extensions

a(10)-a(16) from Alex Chernov, Jan 15 2012

Status

approved