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A232368
T(n,k)=Number of nXk 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or vertically
7
1, 3, 3, 7, 23, 7, 15, 145, 145, 15, 33, 887, 2411, 887, 33, 73, 5487, 39321, 39321, 5487, 73, 161, 33957, 647287, 1704619, 647287, 33957, 161, 355, 210039, 10652849, 74665511, 74665511, 10652849, 210039, 355, 783, 1299219, 175284259, 3271362341
OFFSET
1,2
COMMENTS
Table starts
...1.......3..........7............15................33...................73
...3......23........145...........887..............5487................33957
...7.....145.......2411.........39321............647287.............10652849
..15.....887......39321.......1704619..........74665511...........3271362341
..33....5487.....647287......74665511........8716796353........1017627171097
..73...33957...10652849....3271362341.....1017627171097......316516682114845
.161..210039..175284259..143280358783...118759183620445....98411994699167317
.355.1299219.2884208601.6275473692531.13859593192739275.30598926533212575781
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 2*a(n-1) +a(n-3)
k=2: a(n) = 5*a(n-1) +6*a(n-2) +8*a(n-3) +3*a(n-4) -8*a(n-5) -5*a(n-6)
k=3: [order 21]
k=4: [order 60]
EXAMPLE
Some solutions for n=3 k=4
..0..1..2..2....1..0..2..1....2..2..1..0....1..2..1..1....2..1..2..1
..2..1..1..2....2..1..0..1....0..1..1..1....0..1..2..2....1..1..2..2
..1..2..2..1....2..1..1..2....2..2..2..2....2..2..2..1....2..0..2..2
CROSSREFS
Column 1 is A193641
Column 2 is A232145
Sequence in context: A046631 A100666 A262375 * A333924 A173321 A191498
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 23 2013
STATUS
approved