A204079 Number of nX3 0..3 arrays with every element neighboring horizontally or vertically both a 0 and a 1

0, 4, 132, 256, 5260, 37636, 321696, 2951524, 26486820, 229461904, 2051332140, 18106931844, 160285145184, 1419610292676, 12571883432500, 111281907352576, 985420995488860, 8724655803209956, 77248992679400736, 683971842578913604

Offset

1,2

Comments

Column 3 of A204084

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -3*a(n-3) -53*a(n-4) -204*a(n-5) +6138*a(n-6) -54492*a(n-7) +9384*a(n-8) -51288*a(n-9) +466488*a(n-10) -62016*a(n-11) -306128*a(n-12) +3916128*a(n-13) +2633856*a(n-15) -33362176*a(n-16) for n>19

Example

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

Crossrefs

Sequence in context: A194536 A064227 A353794 * A252172 A192837 A338040

Adjacent sequences: A204076 A204077 A204078 * A204080 A204081 A204082

Keyword

nonn

Author

R. H. Hardin Jan 10 2012

Status

approved