A196489 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,3,0,1,4 for x=0,1,2,3,4.

1, 5, 23, 99, 435, 1821, 7761, 33445, 142899, 610111, 2610127, 11166323, 47747117, 204171367, 873175939, 3734216551, 15969151905, 68291795495, 292051077171, 1248957218645, 5341159082973, 22841464889713, 97681553556621

Offset: 1

Author

R. H. Hardin Oct 03 2011

Keywords

• nonn

Comments

Every 0 is next to 0 2's, every 1 is next to 1 3's, every 2 is next to 2 0's, every 3 is next to 3 1's, every 4 is next to 4 4's

Column 4 of A196493

Examples

			Some solutions for n=5
..0..0..0..0....1..3..1..1....0..0..0..0....0..0..0..0....1..0..0..0
..0..0..0..1....0..1..1..3....1..3..1..0....1..3..1..1....3..1..1..0
..1..0..1..3....0..1..0..1....0..1..0..0....1..1..1..3....1..1..3..1
..3..1..1..1....0..3..1..0....0..1..0..0....3..1..1..1....0..1..0..0
..1..1..3..1....0..1..0..0....1..3..1..0....1..1..3..1....1..3..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = a(n-1) +5*a(n-2) +25*a(n-3) +48*a(n-4) +51*a(n-5) -25*a(n-6) -59*a(n-7) +13*a(n-8) +77*a(n-9) +36*a(n-10) -11*a(n-11) -31*a(n-12) -17*a(n-13) -2*a(n-14) +3*a(n-15) +a(n-16)