A205305 Number of nX3 0..3 arrays with no occurrence of three equal elements in a row horizontally or vertically, and new values 0..3 introduced in row major order

4, 159, 7445, 381958, 19490790, 996536552, 50933680120, 2603456557653, 133072628448179, 6801873967993408, 347670725973943044, 17770830778194675356, 908337669425005770376, 46428742540607711341143

Offset

1,1

Comments

Column 3 of A205310

Links

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

Formula

Empirical: a(n) = 45*a(n-1) +360*a(n-2) -2443*a(n-3) +752*a(n-4) +1861*a(n-5) +17330*a(n-6) +3931*a(n-7) -55696*a(n-8) -6621*a(n-9) +28764*a(n-10) -5265*a(n-11) -9477*a(n-12) +1080*a(n-13) +1080*a(n-14)

Example

Some solutions for n=5
..0..0..1....0..0..1....0..0..1....0..0..1....0..1..0....0..1..1....0..0..1
..0..2..0....0..1..0....1..2..1....2..0..2....1..0..0....2..1..1....2..0..3
..3..1..1....2..2..1....1..3..2....2..1..1....0..1..1....0..2..0....3..1..1
..2..0..2....1..3..2....0..3..3....0..1..1....1..0..2....3..0..0....0..1..2
..0..1..0....0..1..0....0..1..3....2..2..3....3..0..1....2..1..1....1..2..0

Crossrefs

Sequence in context: A204680 A205156 A268007 * A268047 A278770 A264568

Adjacent sequences: A205302 A205303 A205304 * A205306 A205307 A205308

Keyword

nonn

Author

R. H. Hardin Jan 25 2012

Status

approved