A236003 Number of (n+1) X (1+1) 0..3 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2 X 2 subblock.

88, 508, 2960, 17464, 104112, 626480, 3800832, 23225504, 142804544, 882709824, 5480742912, 34158067072, 213553551104, 1338584619776, 8408369438720, 52910011296256, 333414947431424, 2103480056239104, 13283213826064384

Offset

1,1

Links

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

Formula

Empirical: a(n) = 16*a(n-1) - 86*a(n-2) + 156*a(n-3) + 48*a(n-4) - 256*a(n-5) - 64*a(n-6).

Empirical g.f.: 4*x*(22 - 225*x + 600*x^2 + 16*x^3 - 1056*x^4 - 256*x^5) / ((1 - 8*x + 14*x^2 + 4*x^3)*(1 - 8*x + 8*x^2 + 16*x^3)). - Colin Barker, Oct 20 2018

Example

Some solutions for n=5:
..0..2....3..2....3..1....3..2....2..3....2..1....1..2....2..1....1..3....0..3
..3..1....2..1....2..2....2..1....2..1....2..3....3..2....1..2....2..2....2..1
..2..2....0..1....0..0....3..0....2..1....1..2....2..3....2..3....1..1....3..2
..1..3....1..2....3..3....2..1....2..1....1..0....1..0....1..2....2..2....2..3
..2..0....0..1....2..2....1..2....2..1....2..3....1..2....1..2....1..3....1..2
..1..1....1..0....1..3....1..2....2..1....1..0....3..2....0..1....2..2....2..1

Crossrefs

Column 1 of A236009.

Sequence in context: A046378 A187176 A236009 * A183839 A297228 A137124

Adjacent sequences: A236000 A236001 A236002 * A236004 A236005 A236006

Keyword

nonn

Author

R. H. Hardin, Jan 18 2014

Status

approved