A253151 Number of (n+1)X(n+1) 0..1 arrays with every 2X2 subblock diagonal minus antidiagonal sum nondecreasing horizontally and vertically

16, 72, 94, 164, 308, 596, 1172, 2324, 4628, 9236, 18452, 36884, 73748, 147476, 294932, 589844, 1179668, 2359316, 4718612, 9437204, 18874388, 37748756, 75497492, 150994964, 301989908, 603979796

Offset

1,1

Comments

Diagonal of A253159

Links

Table of n, a(n) for n=1..26.

Formula

Empirical: a(n) = 3*a(n-1) -2*a(n-2) for n>5

Empirical: a(n) = 18*2^(n-1) + 20 for n>3

Example

Some solutions for n=6
..0..0..0..0..0..0..0....0..1..0..1..1..0..0....0..1..1..1..0..0..0
..1..1..1..1..1..1..1....1..1..0..1..1..0..0....0..1..1..1..0..0..0
..0..0..0..0..0..0..0....1..1..0..1..1..0..0....0..1..1..1..0..0..0
..1..1..1..1..1..1..1....1..1..0..1..1..0..0....0..1..1..1..0..0..0
..0..0..0..0..0..0..0....1..1..0..1..1..0..0....0..1..1..1..0..0..0
..0..0..0..0..0..0..0....1..1..0..1..1..0..0....0..1..1..1..0..0..0
..0..0..0..0..0..0..1....1..1..0..1..1..0..1....0..1..1..1..0..0..0

Crossrefs

Sequence in context: A272964 A232579 A212862 * A339993 A232402 A212513

Adjacent sequences: A253148 A253149 A253150 * A253152 A253153 A253154

Keyword

nonn

Author

R. H. Hardin, Dec 28 2014

Status

approved