A238287 T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with no element greater than all horizontal neighbors or less than all vertical neighbors

4, 16, 16, 50, 204, 50, 144, 1844, 1844, 144, 422, 13948, 42084, 13948, 422, 1268, 105862, 737366, 737366, 105862, 1268, 3823, 850420, 12926271, 27913368, 12926271, 850420, 3823, 11472, 6953993, 245920800, 1058583000, 1058583000, 245920800

Offset

1,1

Comments

Table starts

......4.........16.............50................144.................422

.....16........204...........1844..............13948..............105862

.....50.......1844..........42084.............737366............12926271

....144......13948.........737366...........27913368..........1058583000

....422.....105862.......12926271.........1058583000.........87389474502

...1268.....850420......245920800........44441926832.......8155057418133

...3823....6953993.....4810332239......1931022884277.....790756782942944

..11472...56279542....92790334588.....82508389421874...75089860262272452

..34350..451637564..1767175335274...3470891253761820.7004416705370946171

.102896.3624058880.33631393265283.145872518046542058

Links

R. H. Hardin, Table of n, a(n) for n = 1..97

Formula

Empirical for column k:

k=1: a(n) = 4*a(n-1) -6*a(n-2) +10*a(n-3) -5*a(n-4) +6*a(n-5) -a(n-6) +a(n-7)

k=2: [order 25]

Example

Some solutions for n=3 k=4
..0..2..2..1..1....2..2..1..0..0....0..2..2..0..0....0..0..2..2..0
..0..2..2..1..0....0..0..0..0..0....0..2..2..0..0....0..0..2..2..0
..1..2..2..2..0....0..0..0..1..1....1..3..3..2..0....0..2..2..3..3
..1..2..2..2..1....2..2..0..3..3....1..3..3..3..0....2..3..3..3..3

Crossrefs

Column 1 is A203094(n+1)

Sequence in context: A224050 A224281 A224204 * A223811 A223762 A223850

Adjacent sequences: A238284 A238285 A238286 * A238288 A238289 A238290

Keyword

nonn,tabl

Author

R. H. Hardin, Feb 22 2014

Status

approved