A236120 Number of (n+1) X (1+1) 0..3 arrays colored with the sets of distinct values in every 2 X 2 subblock.

256, 3096, 37584, 455808, 5529360, 67071552, 813596592, 9869111712, 119714700240, 1452167705472, 17615140009200, 213675837978720, 2591938749790992, 31440833634380352, 381384791617780272

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) + 59*a(n-2) + 164*a(n-3) + 264*a(n-4) + 96*a(n-5) - 144*a(n-6).

Empirical g.f.: 8*x*(32 + 195*x + 488*x^2 + 707*x^3 + 216*x^4 - 372*x^5) / (1 - 6*x - 59*x^2 - 164*x^3 - 264*x^4 - 96*x^5 + 144*x^6). - Colin Barker, Oct 20 2018

Example

Some solutions for n=3:
..3..2....3..3....2..1....3..0....1..2....2..2....2..2....3..3....0..1....2..2
..1..2....1..1....1..0....1..3....1..3....2..3....3..2....3..3....3..1....1..3
..3..0....1..0....0..1....3..3....0..3....3..0....0..0....0..3....2..1....0..0
..3..1....0..2....3..1....3..3....3..2....1..3....1..2....1..3....1..2....2..1

Crossrefs

Column 1 of A236123.

Sequence in context: A236296 A138333 A236123 * A205037 A236133 A205033

Adjacent sequences: A236117 A236118 A236119 * A236121 A236122 A236123

Keyword

nonn

Author

R. H. Hardin, Jan 19 2014

Status

approved