A205918 Number of (n+1)X(n+1) 0..3 arrays with the number of clockwise edge increases in every 2X2 subblock equal to one, and every 2X2 determinant nonzero

76, 2684, 67372, 7177505, 160958484, 88272553560, 1371965011892, 8711176002158453, 72211646175697736

Offset

1,1

Comments

Diagonal of A205926

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=4
..3..1..3..1..0....1..1..1..2..1....0..3..1..1..0....1..2..2..0..2
..0..1..1..1..1....1..2..1..1..1....1..3..3..1..1....1..1..2..2..2
..1..1..2..1..3....1..1..1..2..0....1..2..3..3..0....2..1..1..2..1
..2..1..1..1..1....2..1..2..2..3....2..2..2..3..3....1..1..2..2..3
..1..1..2..3..0....2..2..2..3..3....2..3..2..2..3....0..1..1..2..2

Crossrefs

Sequence in context: A153177 A166191 A188400 * A261574 A017792 A035733

Adjacent sequences: A205915 A205916 A205917 * A205919 A205920 A205921

Keyword

nonn

Author

R. H. Hardin Feb 01 2012

Status

approved