A237974 T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.

256, 1494, 1494, 7905, 10014, 7905, 40442, 59014, 59014, 40442, 208210, 357672, 369068, 357672, 208210, 1074202, 2270776, 2609908, 2609908, 2270776, 1074202, 5540337, 14222512, 20123780, 25087700, 20123780, 14222512, 5540337, 28475040

Offset

1,1

Comments

Table starts

.......256........1494.........7905..........40442...........208210

......1494.......10014........59014.........357672..........2270776

......7905.......59014.......369068........2609908.........20123780

.....40442......357672......2609908.......25087700........255374826

....208210.....2270776.....20123780......255374826.......3450339192

...1074202....14222512....149625960.....2480183866......43487194848

...5540337....88114176...1103412332....24232087766.....564910605674

..28475040...550642732...8201125448...242591959184....7417532096096

.146747184..3451069630..61392928964..2393881373820...95620736858354

.755218808.21560822458.454158172752.23436165715384.1224826491964084

Links

R. H. Hardin, Table of n, a(n) for n = 1..180

Formula

Empirical for column k:

k=1: a(n) = 488*a(n-4) +5140*a(n-6) +14624*a(n-8) +12288*a(n-10) for n>13

k=2: [order 17] for n>20

k=3: [order 48] for n>53

Example

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

Crossrefs

Sequence in context: A237150 A237143 A333606 * A237967 A237142 A237135

Adjacent sequences: A237971 A237972 A237973 * A237975 A237976 A237977

Keyword

nonn,tabl

Author

R. H. Hardin, Feb 16 2014

Status

approved