A235432 Number of (n+1) X (1+1) 0..2 arrays with the difference between each 2 X 2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise.

81, 583, 3987, 26091, 167095, 1054515, 6595119, 41000659, 253895775, 1568132115, 9668295199, 59539686963, 366369714879, 2253205840339, 13852423685919, 85142227813107, 523230252672511, 3215084609223699, 19754194228657119

Offset

1,1

Comments

Column 1 of A235437.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) - a(n-2) - 64*a(n-3) - 14*a(n-4) + 88*a(n-5) + 8*a(n-6) - 24*a(n-7).

Empirical g.f.: x*(81 - 65*x - 596*x^2 - 38*x^3 + 800*x^4 + 48*x^5 - 216*x^6) / ((1 - x)*(1 - 2*x - 8*x^2 - 4*x^3)*(1 - 5*x - 8*x^2 + 6*x^3)). - Colin Barker, Mar 19 2018

Example

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

Crossrefs

Cf. A235437.

Sequence in context: A235737 A236490 A235437 * A206064 A359607 A016756

Adjacent sequences: A235429 A235430 A235431 * A235433 A235434 A235435

Keyword

nonn

Author

R. H. Hardin, Jan 10 2014

Status

approved