A183785 Half the number of (n+1) X 3 0..2 arrays with no 2 X 2 subblock having sum 4.

216, 3552, 57966, 948164, 15497634, 253372446, 4142036148, 67714639662, 1106996131802, 18097205612196, 295853182740306, 4836611736951630, 79068975444380772, 1292620478037357518, 21131773136239117962

Offset

1,1

Comments

Column 2 of A183792.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 12*a(n-1) + 90*a(n-2) - 279*a(n-3) - 618*a(n-4) + 2092*a(n-5) - 1344*a(n-6).

Empirical g.f.: 2*x*(108 + 480*x - 2049*x^2 - 3422*x^3 + 13611*x^4 - 9072*x^5) / (1 - 12*x - 90*x^2 + 279*x^3 + 618*x^4 - 2092*x^5 + 1344*x^6). - Colin Barker, Apr 04 2018

Example

Some solutions for 5 X 3:
..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..1....0..0..0
..1..1..2....1..2..1....1..2..1....1..1..1....1..0..2....0..0..0....2..1..0
..1..0..0....2..1..2....2..2..1....2..1..2....1..1..0....2..1..0....0..0..1
..0..0..1....0..2..0....1..2..2....0..2..0....1..0..1....2..0..1....2..1..1
..1..1..0....1..0..1....2..1..1....1..2..1....0..0..1....0..1..0....2..1..0

Crossrefs

Cf. A183792.

Sequence in context: A027364 A017235 A152241 * A282019 A017343 A269190

Adjacent sequences: A183782 A183783 A183784 * A183786 A183787 A183788

Keyword

nonn

Author

R. H. Hardin, Jan 07 2011

Status

approved