A232291 Number of nX4 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or antidiagonally.

15, 587, 20563, 718483, 25116353, 877968487, 30690409685, 1072818688305, 37501616113029, 1310912294899905, 45824453004106979, 1601846669127816785, 55994400002283842181, 1957348909882095004225, 68421391333068584221039

Offset: 1

Author

R. H. Hardin, Nov 22 2013

Keywords

• nonn

Comments

Column 4 of A232295

Examples

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

Links

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

Formula

Empirical: a(n) = 30*a(n-1) +171*a(n-2) +93*a(n-3) -496*a(n-4) -281*a(n-5) +186*a(n-6) +206*a(n-7) -173*a(n-8) +45*a(n-9) -4*a(n-10)