A224199 Number of nX3 0..3 arrays with rows unimodal and antidiagonals nondecreasing

50, 984, 16060, 263516, 4357084, 72105068, 1193130640, 19742052632, 326659600368, 5405039750704, 89433956076272, 1479810123371280, 24485531969701600, 405147434704078656, 6703731985610244736

Offset

1,1

Comments

Column 3 of A224204

Links

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

Formula

Empirical: a(n) = 20*a(n-1) -70*a(n-2) +228*a(n-3) -276*a(n-4) +392*a(n-5) -196*a(n-6) +144*a(n-7)

Example

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

Crossrefs

Sequence in context: A224059 A224045 A224276 * A112890 A231421 A200207

Adjacent sequences: A224196 A224197 A224198 * A224200 A224201 A224202

Keyword

nonn

Author

R. H. Hardin Apr 01 2013

Status

approved