OFFSET
1,3
LINKS
George Jellis, Knight's tours of Four Rank Boards
EXAMPLE
a(3) = 3 because there are two symmetric and one asymmetric tour:
+----+----+----+----+ +----+----+----+----+ +----+----+----+----+
| 8 | 11 | 6 | 3 | | 1 | 4 | 7 | 10 | | 1 | 4 | 7 | 10 |
+----+----+----+----+ +----+----+----+----+ +----+----+----+----+
| 1 | 4 | 9 | 12 | | 8 | 11 | 2 | 5 | | 12 | 9 | 2 | 5 |
+----+----+----+----+ +----+----+----+----+ +----+----+----+----+
| 10 | 7 | 2 | 5 | | 3 | 6 | 9 | 12 | | 3 | 6 | 11 | 8 |
+----+----+----+----+ +----+----+----+----+ +----+----+----+----+
CROSSREFS
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Oct 12 2019
STATUS
approved