A236157 Number of (n+1) X (1+1) 0..2 arrays colored with the sets of distinct values in every 2 X 2 subblock, with new values 0..2 introduced row-major order.

14, 69, 358, 1844, 9522, 49108, 253476, 1307604, 6748036, 34815556, 179654284, 926952404, 4783063596, 24679485652, 127343933580, 657071270292, 3390407179468, 17493950046676, 90266392976908, 465760736729108

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 18*a(n-2) + 16*a(n-3) + 12*a(n-4) - 12*a(n-5) for n>6.

Empirical g.f.: x*(14 + 55*x + 37*x^2 + 20*x^3 - 38*x^4 + 6*x^5) / (1 - x - 18*x^2 - 16*x^3 - 12*x^4 + 12*x^5). - Colin Barker, Oct 20 2018

Example

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

Crossrefs

Column 1 of A236164.

Sequence in context: A249708 A008354 A051879 * A002423 A212751 A212749

Adjacent sequences: A236154 A236155 A236156 * A236158 A236159 A236160

Keyword

nonn

Author

R. H. Hardin, Jan 19 2014

Status

approved