A209730 1/4 the number of (n+1)X3 0..3 arrays with every 2X2 subblock having distinct edge sums.

124, 1096, 9712, 86744, 775096, 6933120, 62007896, 554698328, 4961776976, 44385441816, 397039390488, 3551673425792, 31770878566904, 284202098661272, 2542285677573168, 22741649976952728, 203432011675276088

Offset: 1

Author

R. H. Hardin Mar 12 2012

Keywords

• nonn

Comments

Column 2 of A209736

Examples

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

Links

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

Formula

Empirical: a(n) = 11*a(n-1) +13*a(n-2) -364*a(n-3) +519*a(n-4) +2741*a(n-5) -6099*a(n-6) -4620*a(n-7) +15632*a(n-8) -1696*a(n-9) -8896*a(n-10) +3328*a(n-11)