A205470 Number of (n+1)X4 0..2 arrays with every 2X2 subblock having the same number of equal edges, and new values 0..2 introduced in row major order.

175, 1548, 14639, 147129, 1504556, 15614579, 162976758, 1709130780, 17963198743, 189127385194, 1993106187666, 21019022873891, 221754001074914, 2340228495931166, 24701472352877203, 260760556151955406

Offset: 1

Author

R. H. Hardin Jan 27 2012

Keywords

• nonn

Comments

Column 3 of A205475

Examples

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

Links

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

Formula

Empirical: a(n) = 20*a(n-1) -75*a(n-2) -688*a(n-3) +5022*a(n-4) -496*a(n-5) -63723*a(n-6) +111258*a(n-7) +251463*a(n-8) -817674*a(n-9) -9180*a(n-10) +2101200*a(n-11) -1759426*a(n-12) -1578136*a(n-13) +2839836*a(n-14) -596208*a(n-15) -1049272*a(n-16) +620728*a(n-17) +18624*a(n-18) -96072*a(n-19) +24528*a(n-20) -1728*a(n-21)