A236158 Number of (n+1) X (2+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.

69, 417, 2688, 17406, 112830, 731610, 4743680, 30758256, 199437026, 1293154716, 8384845368, 54367536934, 352520397960, 2285750623774, 14820861258700, 96098815951376, 623107002046964, 4040240581140500, 26197015761022948

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 19*a(n-2) + 24*a(n-3) - a(n-4) - 22*a(n-5) - 11*a(n-6) - 2*a(n-7) - 2*a(n-8).

Empirical g.f.: x*(69 + 210*x + 126*x^2 - 237*x^3 - 399*x^4 - 171*x^5 - 43*x^6 - 27*x^7) / (1 - 3*x - 19*x^2 - 24*x^3 + x^4 + 22*x^5 + 11*x^6 + 2*x^7 + 2*x^8). - Colin Barker, Oct 20 2018

Example

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

Crossrefs

Column 2 of A236164.

Sequence in context: A158736 A262456 A161486 * A253342 A253335 A234832

Adjacent sequences: A236155 A236156 A236157 * A236159 A236160 A236161

Keyword

nonn

Author

R. H. Hardin, Jan 19 2014

Status

approved