A201351 Number of nX6 0..1 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor

5, 36, 273, 2732, 29540, 310036, 3030673, 27104947, 220732437, 1641106829, 11206232481, 70771398891, 416197943012, 2293568841898, 11910310629163, 58569696365494, 273928804681607, 1223107208560736, 5231237485621038

Offset

1,1

Comments

Column 6 of A201353

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) is a polynomial of degree 63 for n>22

Example

Some solutions for n=5
..0..0..0..0..0..0....0..0..0..0..0..0....0..0..0..0..1..1....0..0..0..0..1..1
..0..0..0..0..0..1....0..0..0..0..1..1....0..0..0..1..0..0....0..1..1..1..0..1
..0..0..0..1..1..1....0..0..0..1..0..0....0..0..0..1..1..1....1..0..0..0..0..1
..0..1..1..0..1..0....0..0..1..1..0..1....0..1..1..0..0..0....1..0..1..1..1..0
..1..1..1..0..0..0....1..1..1..1..0..1....1..1..1..1..0..0....1..1..1..1..0..0

Crossrefs

Sequence in context: A164110 A285392 A327091 * A253470 A188899 A052203

Adjacent sequences: A201348 A201349 A201350 * A201352 A201353 A201354

Keyword

nonn

Author

R. H. Hardin Nov 30 2011

Status

approved