A268094 Number of 2 X n 0..2 arrays with every repeated value in every row not one larger and in every column one larger mod 3 than the previous repeated value, and upper left element zero.

3, 27, 243, 2028, 16428, 129792, 1009200, 7756992, 59140800, 448278528, 3383655168, 25462705152, 191189978112, 1433272320000, 10732091092992, 80291457712128, 600321157939200, 4486422252748800, 33517530883227648

Offset

1,1

Links

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

Formula

Empirical: a(n) = 14*a(n-1) - 44*a(n-2) - 88*a(n-3) + 352*a(n-4) + 320*a(n-5) - 256*a(n-6).

Empirical g.f.: 3*x*(1 - 5*x - x^2 + 26*x^3 + 16*x^4 - 16*x^5) / ((1 + 2*x)*(1 - 4*x)*(1 - 8*x + 4*x^2)*(1 - 4*x - 8*x^2)). - Colin Barker, Jan 11 2019

Example

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

Crossrefs

Row 2 of A268092.

Sequence in context: A065100 A035088 A344724 * A013708 A102518 A361842

Adjacent sequences: A268091 A268092 A268093 * A268095 A268096 A268097

Keyword

nonn

Author

R. H. Hardin, Jan 26 2016

Status

approved