A232156 Number of nX3 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, vertically or antidiagonally, and no adjacent values equal

4, 62, 290, 1284, 5902, 27086, 124436, 572080, 2629946, 12090710, 55591878, 255589946, 1175154022, 5403111082, 24842308392, 114220099740, 525160514282, 2414582116408, 11101765510580, 51043677955498, 234688597761528

Offset

1,1

Comments

Column 3 of A232161

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -12*a(n-2) -33*a(n-3) +40*a(n-4) +286*a(n-5) -545*a(n-6) -642*a(n-7) +2651*a(n-8) -1783*a(n-9) -2378*a(n-10) +4407*a(n-11) -1301*a(n-12) -2857*a(n-13) +3373*a(n-14) +157*a(n-15) -2558*a(n-16) +366*a(n-17) +1084*a(n-18) +818*a(n-19) -2988*a(n-20) -2028*a(n-21) +2529*a(n-22) +1294*a(n-23) +328*a(n-24) +582*a(n-25) -122*a(n-26) -180*a(n-27) +47*a(n-28) +21*a(n-29) -3*a(n-30) for n>33

Example

Some solutions for n=7
..1..2..3....1..2..3....0..1..2....1..2..3....2..1..0....0..3..1....2..1..2
..3..1..0....3..1..2....2..0..3....3..0..1....3..2..1....1..2..0....3..0..3
..0..3..2....2..0..3....3..2..1....1..2..0....1..0..2....0..3..2....1..2..1
..2..0..1....3..1..2....1..0..3....0..3..2....2..3..0....2..0..3....3..0..2
..1..3..0....2..3..0....3..2..1....2..0..3....1..2..1....1..2..0....2..3..0
..0..2..1....1..2..1....0..3..0....3..1..2....0..3..0....3..1..3....0..1..2
..3..0..3....0..3..0....1..2..1....0..3..1....2..1..3....2..0..2....2..3..1

Crossrefs

Sequence in context: A326225 A102193 A376736 * A316391 A293968 A222791

Adjacent sequences: A232153 A232154 A232155 * A232157 A232158 A232159

Keyword

nonn

Author

R. H. Hardin, Nov 19 2013

Status

approved