A205514 Number of (n+1)X3 0..2 arrays with the number of clockwise edge increases in every 2X2 subblock differing from each horizontal or vertical neighbor.

360, 2412, 17166, 122232, 864948, 6127554, 43434216, 307791390, 2181099672, 15456520254, 109532942598, 776204639616, 5500580033478, 38979904487142, 276231336095166, 1957515179621772, 13871944501198614, 98303626985179020

Offset

1,1

Comments

Column 2 of A205520

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +12*a(n-2) +59*a(n-3) +73*a(n-4) +36*a(n-5) -15*a(n-6) -32*a(n-7) -24*a(n-8) -8*a(n-9) +2*a(n-10)

Example

Some solutions for n=4
..2..1..2....2..2..2....2..2..2....2..0..2....0..2..2....2..1..2....1..0..2
..2..1..0....1..2..2....1..2..2....1..1..1....2..1..1....1..2..2....1..1..0
..0..2..2....0..2..0....2..1..2....1..0..2....0..0..2....1..2..2....0..2..2
..1..1..0....0..0..2....1..1..0....2..1..1....0..0..0....2..0..2....1..1..0
..1..1..2....2..1..2....0..2..2....0..0..2....1..2..1....2..2..0....0..2..2

Crossrefs

Sequence in context: A236059 A206670 A236991 * A056390 A056380 A234555

Adjacent sequences: A205511 A205512 A205513 * A205515 A205516 A205517

Keyword

nonn

Author

R. H. Hardin, Jan 28 2012

Status

approved