A239532 Number of (n+1) X (3+1) 0..2 arrays with no element equal to all horizontal neighbors or unequal to all vertical neighbors, and new values 0..2 introduced in row major order.

6, 6, 216, 1014, 13254, 98304, 984150, 8368566, 77673624, 687582150, 6243858486, 55924463616, 504631320486, 4535315519334, 40848737643864, 367488643786134, 3308125850845350, 29769598506080256, 267943541451802614

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) + 26*a(n-2) - 166*a(n-3) + 96*a(n-4) + 198*a(n-5) - 81*a(n-6).

Empirical g.f.: 6*(1 - 7*x + 2*x^2 + 21*x^3 - 9*x^4) / ((1 + x)*(1 - 9*x)*(1 - 3*x + x^2)*(1 + 3*x - 9*x^2)). - Colin Barker, Oct 26 2018

Example

Some solutions for n=5:
..0..1..0..2....0..1..0..1....0..1..1..0....0..1..2..0....0..1..2..1
..0..1..0..2....0..1..0..1....0..1..1..0....0..1..2..0....0..1..2..1
..1..0..0..2....0..1..2..1....0..1..2..1....1..0..1..2....2..1..0..1
..1..0..0..2....0..2..2..1....1..2..2..1....1..0..1..2....2..0..0..1
..0..1..1..0....0..2..0..1....1..2..2..1....1..0..2..0....1..0..2..1
..0..1..1..0....0..2..0..1....1..2..2..1....1..0..2..0....1..0..2..1

Crossrefs

Column 3 of A239537.

Sequence in context: A328186 A123190 A244956 * A351793 A370711 A165641

Adjacent sequences: A239529 A239530 A239531 * A239533 A239534 A239535

Keyword

nonn

Author

R. H. Hardin, Mar 21 2014

Status

approved