A203392 Number of nX3 0..3 arrays with every nonzero element less than or equal to some NW, E or S neighbor

1, 185, 7785, 210342, 5666072, 163500122, 4711784187, 134023641768, 3812883352529, 108732629007739, 3100601273660894, 88377350678293866, 2519070713456537742, 71808337430581027703, 2046955733267173360684

Offset

1,2

Comments

Column 3 of A203397

Links

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

Formula

Empirical: a(n) = 64*a(n-1) -1706*a(n-2) +30044*a(n-3) -404960*a(n-4) +4099850*a(n-5) -30536063*a(n-6) +171426725*a(n-7) -757277294*a(n-8) +2720190934*a(n-9) -8042244702*a(n-10) +19622828742*a(n-11) -39893786618*a(n-12) +68882173897*a(n-13) -102395699308*a(n-14) +129694096680*a(n-15) -135121114784*a(n-16) +110642585924*a(n-17) -68014475760*a(n-18) +29890935888*a(n-19) -8795890848*a(n-20) +1545208704*a(n-21) -122145408*a(n-22) for n>23

Example

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

Crossrefs

Sequence in context: A209373 A207076 A189181 * A197646 A015273 A214605

Adjacent sequences: A203389 A203390 A203391 * A203393 A203394 A203395

Keyword

nonn

Author

R. H. Hardin Jan 01 2012

Status

approved