A202454 - OEIS

A202454

Number of (n+2) X (n+2) binary arrays with consecutive windows of three bits considered as a binary number nondecreasing in every row and column.

512, 1194, 3362, 10918, 38478, 141192, 528390, 1998486, 7609118, 29110180, 111787002, 430618204, 1663208690, 6438719028, 24976207182, 97056810102, 377757631038, 1472369063940, 5746130037258, 22451082059892, 87812623596642, 343791474169608, 1347153935661282, 5283149717263548

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..68

FORMULA

Conjecture: a(n) ~ c * 4^n / sqrt(n), where c = 95.3480396... - Vaclav Kotesovec, Feb 16 2026

EXAMPLE

Some solutions for 6 X 6:

..0..0..0..1..0..0....0..0..0..0..1..1....0..0..0..0..0..0....0..0..0..0..0..1

..0..0..0..1..0..0....0..0..0..1..1..1....0..0..0..0..0..0....0..0..0..1..0..1

..0..0..0..1..1..1....0..0..1..1..1..1....0..0..0..0..0..1....0..0..0..1..0..1