A219405 Unmatched value maps: number of n X 3 binary arrays indicating the locations of corresponding elements not equal to any horizontal or antidiagonal neighbor in a random 0..2 n X 3 array.

4, 28, 181, 1180, 7687, 50077, 326233, 2125270, 13845268, 90196219, 587591326, 3827916001, 24937299865, 162456261409, 1058335787620, 6894622770400, 44915634248581, 292606900638904, 1906213721217931, 12418199102692513

Offset

1,1

Comments

Column 3 of A219410.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) + 15*a(n-2) + 9*a(n-3).

Empirical g.f.: x*(2 + 3*x)^2 / (1 - 4*x - 15*x^2 - 9*x^3). - Colin Barker, Jul 26 2018

Example

Some solutions for n=3:
..1..0..0....1..0..0....1..0..0....0..0..1....1..0..1....1..1..1....0..0..0
..1..0..1....1..1..0....1..0..1....0..1..0....0..0..0....1..1..1....0..0..0
..0..0..0....0..0..0....1..1..1....0..0..1....1..0..0....1..1..1....0..1..1

Crossrefs

Cf. A219410.

Sequence in context: A264707 A216211 A366810 * A391514 A001396 A155611

Adjacent sequences: A219402 A219403 A219404 * A219406 A219407 A219408

Keyword

nonn

Author

R. H. Hardin, Nov 19 2012

Status

approved