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

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

R. H. Hardin, Table of n, a(n) for n = 1..759

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

Adjacent sequences: A250953 A250954 A250955 * A250957 A250958 A250959

Keyword

nonn,tabl

Author

R. H. Hardin, Nov 28 2014

Status

approved