[go: up one dir, main page]

login
A238323
T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with no element greater than all horizontal neighbors or less than all vertical neighbors
8
3, 9, 9, 22, 67, 22, 51, 376, 376, 51, 121, 1867, 4294, 1867, 121, 292, 9489, 41046, 41046, 9489, 292, 704, 50232, 405636, 721939, 405636, 50232, 704, 1691, 267174, 4245918, 13265123, 13265123, 4245918, 267174, 1691, 4059, 1408341, 44773061
OFFSET
1,1
COMMENTS
Table starts
....3.......9.........22............51.............121................292
....9......67........376..........1867............9489..............50232
...22.....376.......4294.........41046..........405636............4245918
...51....1867......41046........721939........13265123..........261676376
..121....9489.....405636......13265123.......459256128........17315827838
..292...50232....4245918.....261676376.....17315827838......1266938409578
..704..267174...44773061....5206684654....658399071392.....93481623913793
.1691.1408341..466364332..102053610873..24577532667851...6747651769489946
.4059.7395987.4831077908.1987295524193.910817281935043.483084194221969236
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 3*a(n-1) -3*a(n-2) +4*a(n-3) -a(n-4) +a(n-5)
k=2: [order 13]
k=3: [order 43]
EXAMPLE
Some solutions for n=3 k=4
..2..2..2..2..0....2..2..1..0..0....2..2..2..1..1....2..2..2..1..0
..2..2..2..0..0....1..1..0..0..0....0..2..2..1..1....2..2..1..1..0
..2..2..2..0..0....1..1..0..0..0....0..2..2..1..1....0..0..1..1..0
..2..2..2..1..1....1..1..2..2..1....2..2..2..1..1....0..0..1..1..0
CROSSREFS
Column 1 is A202882(n+1)
Sequence in context: A224057 A224310 A224374 * A223742 A223725 A223831
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Feb 24 2014
STATUS
approved