A237569 Number of (n+1)X(1+1) 0..3 arrays with the upper median minus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.

256, 1876, 13924, 103264, 769680, 5705156, 42501300, 315065200, 2347267424, 17400203636, 129631996580, 960959725312, 7159191300272, 53070925060004, 395380448791316, 2930946979641872, 21835672557183872, 161867373265982548

Offset: 1

Author

R. H. Hardin, Feb 09 2014

Keywords

• nonn

Comments

Column 1 of A237574

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 23*a(n-2) +1473*a(n-4) +15833*a(n-6) +60176*a(n-8) +65344*a(n-10) -70656*a(n-12) -139264*a(n-14) for n>15