OFFSET
1,2
COMMENTS
EXAMPLE
Some solutions for n=3
..1..1..0....0..1..1....0..0..0....1..1..1....0..1..0....1..0..0....0..0..1
..1..0..1....0..0..0....0..0..1....1..1..0....0..0..0....0..0..1....1..0..1
..1..0..0....1..0..0....1..0..0....0..1..0....1..1..1....0..0..0....1..1..0
MATHEMATICA
Table[n^2 - (First[Dimensions[NullSpace[AdjacencyMatrix[GridGraph[{n, n}]] + IdentityMatrix[n*n], Modulus->2]]]), {n, 1, 40}] (* Vincenzo Librandi, Feb 10 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 07 2012
EXTENSIONS
More terms from Vincenzo Librandi, Feb 10 2017
STATUS
approved