A253432 Number of (n+1) X (5+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.

181, 174, 192, 228, 300, 444, 732, 1308, 2460, 4764, 9372, 18588, 37020, 73884, 147612, 295068, 589980, 1179804, 2359452, 4718748, 9437340, 18874524, 37748892, 75497628, 150995100, 301990044, 603979932, 1207959708, 2415919260, 4831838364

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) for n>3.

Empirical: a(n) = 9*2^(n-1) + 156 for n>1.

Empirical g.f.: x*(181 - 369*x + 32*x^2) / ((1 - x)*(1 - 2*x)). - Colin Barker, Dec 12 2018

Example

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

Crossrefs

Column 5 of A253435.

Sequence in context: A074811 A036200 A357657 * A218977 A253439 A175789

Adjacent sequences: A253429 A253430 A253431 * A253433 A253434 A253435

Keyword

nonn

Author

R. H. Hardin, Dec 31 2014

Status

approved