A206668 T(n,k) = number of (n+1) X (k+1) 0..2 arrays with every 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward and upward neighbors.

81, 423, 423, 2286, 2691, 2286, 12477, 17844, 17844, 12477, 68253, 119727, 166605, 119727, 68253, 373644, 815847, 1637151, 1637151, 815847, 373644, 2046027, 5593611, 16537155, 25229685, 16537155, 5593611, 2046027, 11205045, 38594841

Offset

1,1

Comments

Table starts

.......81.......423........2286.........12477...........68253............373644

......423......2691.......17844........119727..........815847...........5593611

.....2286.....17844......166605.......1637151........16537155.........170170494

....12477....119727.....1637151......25229685.......404408697........6593653335

....68253....815847....16537155.....404408697.....10351091007......269149632948

...373644...5593611...170170494....6593653335....269149632948....11143560422013

..2046027..38594841..1770039198..108688211619...7050554283159...464729380449429

.11205045.267189276.18532885713.1799150533260.185345018259540.19426122492513648

Links

R. H. Hardin, Table of n, a(n) for n = 1..160

Example

Some solutions for n=4, k=3:
..2..1..2..1....0..2..2..0....1..0..1..2....1..2..2..0....0..1..0..0
..0..1..0..1....2..2..0..0....0..1..2..0....0..1..0..0....2..2..2..1
..2..1..2..1....2..0..0..1....1..2..1..2....2..1..0..1....0..1..0..0
..0..0..2..0....0..0..1..1....2..0..2..0....1..1..1..1....2..1..2..1
..2..1..1..1....2..0..0..1....0..1..0..1....2..2..2..1....0..0..0..1

Crossrefs

Sequence in context: A253449 A236148 A205986 * A238180 A206414 A205979

Adjacent sequences: A206665 A206666 A206667 * A206669 A206670 A206671

Keyword

nonn,tabl

Author

R. H. Hardin, Feb 11 2012

Status

approved