A278803 Number of nX4 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order.

15, 154, 1439, 12958, 110455, 870473, 6275546, 41370842, 250517485, 1402100369, 7299678838, 35565305995, 163045228099, 706720556002, 2908736101561, 11411036414661, 42812862296055, 154084456853488, 533397095123831

Offset

1,1

Comments

Column 4 of A278807.

Links

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

R. H. Hardin, Empirical polynomial of degree 44

Formula

Empirical polynomial of degree 44 (see link above)

Example

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

Crossrefs

Cf. A278807.

Sequence in context: A370765 A334356 A017389 * A157380 A098685 A223995

Adjacent sequences: A278800 A278801 A278802 * A278804 A278805 A278806

Keyword

nonn

Author

R. H. Hardin, Nov 28 2016

Status

approved