A232510 Number of (n+1)X(3+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally, with no adjacent elements equal

16, 32, 128, 400, 1344, 4416, 14608, 48224, 159296, 526096, 1737600, 5738880, 18954256, 62601632, 206759168, 682879120, 2255396544, 7449068736, 24602602768, 81256877024, 268373233856, 886376578576, 2927502969600, 9668885487360

Offset

1,1

Comments

Column 3 of A232515

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) +a(n-3).

Empirical: G.f.: -16*x / ( (1+x)*(x^2+3*x-1) ), which means a(n) is 16 times 1, 2, 8, 25, 84, 276 and so on with pairs of adjacent numbers summing to A006190. - R. J. Mathar, Nov 23 2014

Example

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

Crossrefs

Sequence in context: A115686 A088112 A272697 * A339356 A282832 A331420

Adjacent sequences: A232507 A232508 A232509 * A232511 A232512 A232513

Keyword

nonn

Author

R. H. Hardin, Nov 25 2013

Status

approved