A183772 T(n,k) = 1/32 the number of (n+1) X (k+1) binary arrays with equal numbers of 2 X 2 subblocks with sum mod two being 0 and 1.

0, 1, 1, 0, 6, 0, 12, 40, 40, 12, 0, 280, 0, 280, 0, 160, 2016, 7392, 7392, 2016, 160, 0, 14784, 0, 205920, 0, 14784, 0, 2240, 109824, 1555840, 5912192, 5912192, 1555840, 109824, 2240, 0, 823680, 0, 173065984, 0, 173065984, 0, 823680, 0, 32256, 6223360

Offset

1,5

Comments

Table starts

.....0........1...........0..............12..................0

.....1........6..........40.............280...............2016

.....0.......40...........0............7392..................0

....12......280........7392..........205920............5912192

.....0.....2016...........0.........5912192..................0

...160....14784.....1555840.......173065984........19855042560

.....0...109824...........0......5134924800..................0

..2240...823680...346131968....153876579840.....70577422755840

.....0..6223360...........0...4646469273600..................0

.32256.47297536.79420170240.141154845511680.258888921984516096

Links

R. H. Hardin, Table of n, a(n) for n = 1..220

Example

Some solutions for 4 X 3:
..0..1..0....1..1..0....1..0..0....0..1..1....1..1..1....0..0..0....0..0..1
..0..1..1....0..1..0....0..1..0....1..0..1....0..0..0....1..0..0....1..1..1
..0..1..1....1..1..0....1..0..0....1..0..0....1..0..1....1..0..1....0..0..1
..1..1..0....1..1..1....0..1..0....1..1..1....0..1..1....0..1..1....1..0..1

Crossrefs

Column 1 is A098400(n/2-1).

Column 2 is A069720.

Sequence in context: A256856 A028603 A205966 * A240821 A320146 A283999

Adjacent sequences: A183769 A183770 A183771 * A183773 A183774 A183775

Keyword

nonn,tabl

Author

R. H. Hardin, Jan 06 2011

Status

approved