A205584 Number of (n+1) X 3 0..2 arrays with no 2 X 2 subblock having the same number of equal edges as its horizontal or vertical neighbors, and new values 0..2 introduced in row major order.

74, 550, 4220, 32500, 248940, 1910922, 14668206, 112560786, 863863526, 6629842280, 50880821560, 390488098388, 2996825524800, 22999305690670, 176509524902826, 1354632729727342, 10396208030732474, 79786307537199012

Offset: 1

Author

R. H. Hardin, Jan 29 2012

Keywords

• nonn

Comments

Column 2 of A205590.

Examples

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

Links

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

Crossrefs

Cf. A205590.

Formula

Empirical: a(n) = 3*a(n-1) +24*a(n-2) +82*a(n-3) +83*a(n-4) -107*a(n-5) +30*a(n-6) +250*a(n-7).

Empirical g.f.: 2*x*(37 + 164*x + 397*x^2 + 286*x^3 - 541*x^4 + 165*x^5 + 1125*x^6) / (1 - 3*x - 24*x^2 - 82*x^3 - 83*x^4 + 107*x^5 - 30*x^6 - 250*x^7). - Colin Barker, Jun 12 2018