A201625 T(n,k)=Number of nXk 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.

0, 4, 4, 4, 16, 4, 10, 56, 56, 10, 16, 211, 378, 211, 16, 26, 718, 3699, 3699, 718, 26, 40, 2271, 31802, 91223, 31802, 2271, 40, 59, 6654, 256836, 2111763, 2111763, 256836, 6654, 59, 84, 18191, 1877283, 45733593, 136175057, 45733593, 1877283, 18191, 84

Offset

1,2

Comments

Table starts

...0......4.........4...........10.............16..............26

...4.....16........56..........211............718............2271

...4.....56.......378.........3699..........31802..........256836

..10....211......3699........91223........2111763........45733593

..16....718.....31802......2111763......136175057......8368969235

..26...2271....256836.....45733593.....8368969235...1492809994673

..40...6654...1877283....891142897...464328365996.242036871702096

..59..18191..12466658..15644678596.23135668030252

..84..46767..75830797.249289360661

.116.113873.426330762

Links

R. H. Hardin, Table of n, a(n) for n = 1..84

Example

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

Crossrefs

Sequence in context: A382708 A141666 A102127 * A223824 A218056 A218651

Adjacent sequences: A201622 A201623 A201624 * A201626 A201627 A201628

Keyword

nonn,tabl

Author

R. H. Hardin, Dec 03 2011

Status

approved