A237550 Number of (n+1) X (1+1) 0..2 arrays with the maximum minus the upper median of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one.

81, 312, 1240, 4752, 19128, 72736, 290112, 1110080, 4459296, 16979328, 67827328, 259259648, 1040224128, 3964054016, 15850143744, 60545315840, 242745766400, 925519968256, 3702814799872, 14138549342208, 56660164196352

Offset

1,1

Links

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

Formula

Empirical: a(n) = 192*a(n-4) + 608*a(n-6) + 400*a(n-8) for n>9.

Empirical g.f.: x*(81 + 312*x + 1240*x^2 + 4752*x^3 + 3576*x^4 + 12832*x^5 + 2784*x^6 + 8000*x^7 + 400*x^8) / (1 - 192*x^4 - 608*x^6 - 400*x^8). - Colin Barker, Oct 22 2018

Example

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

Crossrefs

Column 1 of A237557.

Sequence in context: A237703 A237696 A237557 * A237567 A237560 A237332

Adjacent sequences: A237547 A237548 A237549 * A237551 A237552 A237553

Keyword

nonn

Author

R. H. Hardin, Feb 09 2014

Status

approved