A238929 T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with no element greater than all horizontal neighbors or equal to all vertical neighbors.

12, 116, 36, 782, 864, 144, 5008, 13090, 13456, 540, 34302, 191086, 611524, 176224, 2052, 238418, 3025468, 25080064, 22636472, 2391340, 7776, 1646042, 48511734, 1176627204, 2531484558, 873385842, 32225410, 29484, 11326068, 773430790

Offset: 1

Author

R. H. Hardin, Mar 07 2014

Keywords

• nonn
• tabl

Comments

Table starts

.....12........116............782...............5008..................34302

.....36........864..........13090.............191086................3025468

....144......13456.........611524...........25080064.............1176627204

....540.....176224.......22636472.........2531484558...........330899764092

...2052....2391340......873385842.......265992385206.........98434762200590

...7776...32225410....33476445936.....27816714540010......29028870095730324

..29484..434883190..1285018853980...2912187511240098....8576772023696061986

.111780.5866480970.49292627209040.304661966072695432.2532114793289297959122

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..83

Formula

Empirical for column k:

k=1: a(n) = 3*a(n-1) +3*a(n-2)

k=2: [order 29]

Empirical for row n:

n=1: [linear recurrence of order 18]