A263793 Number of (n+1) X (n+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits, and rows and columns lexicographically nonincreasing.

2, 2, 7, 7, 61, 616, 62904, 20141827

Offset

1,1

Comments

Diagonal of A263799.

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for n=5:
..1..1..1..1..0..0....1..1..1..1..0..0....1..1..1..1..0..0....1..1..1..1..0..0
..1..1..1..1..0..0....1..1..0..0..1..1....1..1..1..1..0..0....1..1..1..1..0..0
..1..1..0..0..1..1....1..0..1..0..1..0....0..0..0..0..1..1....1..1..0..0..0..0
..1..1..0..0..1..1....1..0..0..1..0..0....0..0..0..0..1..1....1..1..0..0..0..0
..0..0..0..0..1..1....0..0..1..0..0..1....0..0..0..0..1..1....1..0..1..0..1..0
..0..0..0..0..1..1....0..0..0..0..0..0....0..0..0..0..1..1....1..0..1..0..1..0

Crossrefs

Cf. A263799.

Sequence in context: A300952 A195326 A263868 * A232647 A379390 A091665

Adjacent sequences: A263790 A263791 A263792 * A263794 A263795 A263796

Keyword

nonn,more

Author

R. H. Hardin, Oct 26 2015

Status

approved