A209728 1/4 the number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having distinct edge sums.

22, 1096, 137888, 47572464, 45147495264, 121396901813560, 914481225452329872, 19676655455650623737848

Offset: 1

Author

R. H. Hardin Mar 12 2012

Keywords

• nonn

Comments

Diagonal of A209736

Examples

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