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

1,1

Comments

Column 2 of A205590.

Links

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

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

Example

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

Crossrefs

Cf. A205590.

Sequence in context: A296025 A204362 A321114 * A280402 A250913 A186124

Adjacent sequences: A205581 A205582 A205583 * A205585 A205586 A205587

Keyword

nonn

Author

R. H. Hardin, Jan 29 2012

Status

approved