A235948 Number of (n+1) X (2+1) 0..2 arrays colored with the upper median value of each 2 X 2 subblock.

294, 722, 1372, 2660, 5034, 9752, 18468, 35794, 67924, 131474, 251786, 485354, 926434, 1789970, 3433586, 6602990, 12649018, 24390182, 46809866, 89947622, 172622482, 332388566, 638104130, 1225937510, 2354814226, 4530138566

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-3) + 10*a(n-4) - 12*a(n-7) - 6*a(n-8) for n>12.

Empirical g.f.: 2*x*(147 + 361*x + 686*x^2 + 889*x^3 - 36*x^4 - 792*x^5 - 1616*x^6 - 1190*x^7 - 622*x^8 - 327*x^9 - 62*x^10 + 5*x^11) / (1 - 3*x^3 - 10*x^4 + 12*x^7 + 6*x^8). - Colin Barker, Oct 20 2018

Example

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

Crossrefs

Column 2 of A235954.

Sequence in context: A367207 A255104 A212724 * A250752 A235007 A235002

Adjacent sequences: A235945 A235946 A235947 * A235949 A235950 A235951

Keyword

nonn

Author

R. H. Hardin, Jan 17 2014

Status

approved