A278728 Number of n X 2 0..3 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake.

6, 152, 1947, 17352, 121520, 712406, 3633649, 16547278, 68531079, 261693631, 931194981, 3113638802, 9849622993, 29642927267, 85271613063, 235393492799, 625708778733, 1606286648601, 3992748071821, 9631887926896, 22595573914587

Offset

1,1

Comments

Column 2 of A278734.

Links

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

R. H. Hardin, Empirical polynomial of degree 28

Formula

Empirical polynomial of degree 28 (see link above).

Example

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

Crossrefs

Cf. A278734.

Sequence in context: A168654 A147796 A003766 * A221689 A354752 A319036

Adjacent sequences: A278725 A278726 A278727 * A278729 A278730 A278731

Keyword

nonn

Author

R. H. Hardin, Nov 27 2016

Status

approved