OFFSET
1,1
COMMENTS
The initial 2 should probably be a 1, see: A011260. This would change all terms to: a(2) = 0 because of the singular determinant[1,1,2,2] = 0; a(3) = 52; a(4) = -34848; a(5) = -2211008492544.
EXAMPLE
a(2) = 2 =
|2 1|
|2 2|.
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Jonathan Vos Post, May 27 2006
STATUS
approved