|
| |
|
|
A183730
|
|
1/16 the number of (n+1)X2 0..7 arrays with every 2X2 subblock strictly increasing clockwise or anticlockwise with one decrease, and at least two adjacent blocks having the same increasing direction
|
|
1
|
|
|
|
0, 21, 563, 9403, 135578, 1814815, 23204876, 287769879, 3491293862, 41667398364, 490998416023, 5727556631915, 66266101711488, 761498455531330, 8701271226331052, 98948856313647335, 1120614615517688964
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
Column 1 of A183738
|
|
|
LINKS
|
R. H. Hardin, Table of n, a(n) for n = 1..200
|
|
|
FORMULA
|
Empirical: a(n)=18*a(n-1)-46*a(n-2)-342*a(n-3)-33*a(n-4)+435*a(n-5)-157*a(n-6)-37*a(n-7)+21*a(n-8)-2*a(n-9)
|
|
|
EXAMPLE
|
Some solutions with the first block increasing clockwise for 3X2
..4..5....6..0....1..2....1..2....2..4....4..5....7..0....2..3....0..2....0..2
..2..6....5..1....7..4....0..3....0..5....1..6....6..1....1..4....7..3....6..3
..1..7....4..2....6..5....7..4....7..6....0..7....4..3....0..7....6..4....5..4
...
...R.......R.......R.......R.......R.......R.......R.......R.......R.......R...
...R.......R.......R.......R.......R.......R.......R.......R.......R.......R...
|
|
|
CROSSREFS
|
Sequence in context: A015255 A034789 A194022 * A199254 A199199 A089457
Adjacent sequences: A183727 A183728 A183729 * A183731 A183732 A183733
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
R. H. Hardin Jan 06 2011
|
|
|
STATUS
|
approved
|
| |
|
|
