A210089 Number of (n+1) X 3 0..2 arrays containing all values 0..2 with every 2 X 2 subblock having one or two distinct values, and new values 0..2 introduced in row major order.

9, 169, 2370, 29650, 348621, 3950131, 43701168, 475700584, 5119557747, 54648710593, 579871850742, 6125816087470, 64500385137993, 677459176188079, 7102151283474060, 74349727667778004, 777498094039168623

Offset

1,1

Comments

Column 2 of A210095.

Links

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

Formula

Empirical: a(n) = 20*a(n-1) - 112*a(n-2) + 122*a(n-3) + 61*a(n-4) - 106*a(n-5) + 16*a(n-6).

Empirical g.f.: x*(9 - 11*x - 2*x^2 + 80*x^3 - 106*x^4 + 16*x^5) / ((1 - x)*(1 - 8*x)*(1 - 11*x + 5*x^2 + 11*x^3 - 2*x^4)). - Colin Barker, Jul 14 2018

Example

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

Crossrefs

Cf. A210095.

Sequence in context: A223289 A281996 A017306 * A243949 A202836 A052774

Adjacent sequences: A210086 A210087 A210088 * A210090 A210091 A210092

Keyword

nonn

Author

R. H. Hardin, Mar 17 2012

Status

approved