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A250956
T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with no 2X2 subblock having its maximum diagonal element less than its minimum antidiagonal element
7
15, 56, 56, 209, 392, 209, 780, 2744, 2744, 780, 2911, 19208, 36016, 19208, 2911, 10864, 134456, 472712, 472712, 134456, 10864, 40545, 941192, 6204344, 11633448, 6204344, 941192, 40545, 151316, 6588344, 81431944, 286298344, 286298344
OFFSET
1,1
COMMENTS
Table starts
.....15.......56.........209...........780.............2911..............10864
.....56......392........2744.........19208...........134456.............941192
....209.....2744.......36016........472712..........6204344...........81431944
....780....19208......472712......11633448........286298344.........7045780240
...2911...134456.....6204344.....286298344......13211127617.......609622239024
..10864...941192....81431944....7045780240.....609622239024.....52746349035592
..40545..6588344..1068793208..173396103624...28130774228952...4563772381621072
.151316.46118408.14027896712.4267264603784.1298083303266168.394871276236514256
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 4*a(n-1) -a(n-2)
k=2: a(n) = 7*a(n-1)
k=3: a(n) = 15*a(n-1) -24*a(n-2) -8*a(n-3)
k=4: a(n) = 27*a(n-1) -57*a(n-2) -46*a(n-3) +30*a(n-4)
k=5: [order 7]
k=6: [order 9]
k=7: [order 16]
EXAMPLE
Some solutions for n=3 k=4
..0..0..1..0..1....0..1..0..0..0....0..0..0..1..1....0..1..0..1..1
..0..0..0..1..1....0..1..1..1..0....0..1..0..0..0....0..1..0..0..0
..0..1..1..1..0....0..0..0..1..1....0..0..1..0..0....0..0..0..0..0
..0..0..1..1..0....1..1..0..0..1....1..0..1..0..1....0..1..0..0..1
CROSSREFS
Column 1 is A001353(n+2)
Column 2 is A003950(n+1)
Sequence in context: A119136 A036522 A227219 * A243318 A304295 A228322
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 28 2014
STATUS
approved