login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A232406
T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or vertically, with no adjacent elements equal
8
4, 4, 4, 8, 16, 8, 16, 20, 20, 16, 28, 72, 52, 72, 28, 52, 124, 176, 176, 124, 52, 96, 356, 484, 1120, 484, 356, 96, 176, 664, 1500, 2788, 2788, 1500, 664, 176, 324, 1808, 4416, 16884, 13532, 16884, 4416, 1808, 324, 596, 3572, 13220, 44528, 71888, 71888, 44528
OFFSET
1,1
COMMENTS
Table starts
...4....4......8......16.......28.........52..........96..........176
...4...16.....20......72......124........356.........664.........1808
...8...20.....52.....176......484.......1500........4416........13220
..16...72....176....1120.....2788......16884.......44528.......255432
..28..124....484....2788....13532......71888......370876......1936620
..52..356...1500...16884....71888.....798692.....3508240.....38129964
..96..664...4416...44528...370876....3508240....31802528....296151320
.176.1808..13220..255432..1936620...38129964...296151320...5824262024
.324.3572..39524..706796.10086748..171206912..2734362948..45696457832
.596.9148.117892.3869856.52577472.1824149740.25388000332.894239301036
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2) +a(n-3)
k=2: [order 9]
k=3: [order 12]
k=4: [order 29]
k=5: [order 56]
EXAMPLE
Some solutions for n=4 k=4
..0..1..2..0..1....0..1..0..1..2....2..1..2..1..2....0..1..2..1..2
..1..2..0..1..2....1..2..1..2..1....1..0..1..0..1....1..2..1..0..1
..2..1..2..0..1....2..1..0..1..0....0..1..0..1..2....0..1..0..1..0
..1..0..1..2..0....1..2..1..0..1....1..2..1..2..1....1..2..1..2..1
..2..1..0..1..2....0..1..0..1..2....2..1..0..1..0....0..1..0..1..2
CROSSREFS
Column 1 is 4*A000073(n+1)
Sequence in context: A377468 A167184 A276113 * A322040 A085071 A341324
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 23 2013
STATUS
approved