A253537 Number of (n+2) X (1+2) 0..1 arrays with every 3 X 3 subblock diagonal maximum minus antidiagonal minimum nonincreasing horizontally and nondecreasing vertically.

512, 3328, 20480, 119040, 679936, 3825920, 21426176, 119525632, 665944064, 3706601728, 20624052224, 114725138688, 638126694400, 3549162447104, 19739468705792, 109783594930432, 610572175917056, 3395741380509952

Offset

1,1

Comments

Column 1 of A253544.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) - 7*a(n-2) - 56*a(n-3) + 120*a(n-4) - 64*a(n-5).

Empirical g.f.: 256*x*(2 - 3*x - 10*x^2 + 28*x^3 - 16*x^4) / ((1 - x)*(1 - 7*x + 8*x^2)*(1 - 8*x^2)). - Colin Barker, Mar 20 2018

Example

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

Crossrefs

Cf. A253544.

Sequence in context: A253856 A253871 A253544 * A254390 A253985 A253978

Adjacent sequences: A253534 A253535 A253536 * A253538 A253539 A253540

Keyword

nonn

Author

R. H. Hardin, Jan 03 2015

Status

approved