A235443 Number of (n+1) X (2+1) 0..1 arrays with the difference between each 2 X 2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise.

58, 382, 2476, 15936, 102376, 657290, 4219322, 27083638, 173846264, 1115891712, 7162725052, 45976338618, 295114433334, 1894290182854, 12159131749324, 78047432228320, 500973408338488, 3215664483364362, 20640812260995146

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) - 8*a(n-2) - 16*a(n-3) + 12*a(n-4) + 14*a(n-5) - a(n-6) - 2*a(n-7).

Empirical g.f.: 2*x*(29 - 41*x - 58*x^2 + 56*x^3 + 56*x^4 - 5*x^5 - 8*x^6) / ((1 - x - x^2)^2*(1 - 6*x - 3*x^2 + 2*x^3)). - Colin Barker, Oct 19 2018

Example

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

Crossrefs

Column 2 of A235449.

Sequence in context: A250920 A235673 A235730 * A235511 A255684 A156639

Adjacent sequences: A235440 A235441 A235442 * A235444 A235445 A235446

Keyword

nonn

Author

R. H. Hardin, Jan 10 2014

Status

approved