A183771 1/32 the number of (n+1) X 9 binary arrays with equal numbers of 2 X 2 subblocks with sum mod two being 0 and 1.

2240, 823680, 346131968, 153876579840, 70577422755840, 33021546171494400, 15664518350357381120, 7506428481300850827264, 3625062729947846895239168, 1761398107886979915147182080, 860111024347049203759900262400

Offset

1,1

Comments

Column 8 of A183772.

Links

R. H. Hardin, Table of n, a(n) for n = 1..29

Example

Some solutions for 3 X 9:
..0..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0..1
..0..0..1..1..0..0..0..1..0....0..1..1..1..1..0..0..1..0
..0..1..0..1..1..1..0..1..0....1..0..1..0..1..0..0..0..0

Crossrefs

Sequence in context: A038728 A002520 A337416 * A271470 A263912 A251051

Adjacent sequences: A183768 A183769 A183770 * A183772 A183773 A183774

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved