OFFSET
0,4
COMMENTS
For n>1, number of ways to place two dominoes horizontally on an n X n chessboard.
LINKS
MATHEMATICA
Table[n/2 (n^3-2n^2-2n+5), {n, 0, 40}] (* or *) LinearRecurrence[{5, -10, 10, -5, 1}, {0, 1, 1, 12, 58}, 40] (* Harvey P. Dale, Jul 19 2018 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ralf Stephan, Jun 09 2014
STATUS
approved