A230610 Number of nX4 0..2 arrays x(i,j) with each element horizontally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero

0, 2, 30, 348, 3956, 44916, 509978, 5790456, 65747178, 746521190, 8476319172, 96243740012, 1092792451740, 12408031373682, 140886078048560, 1599680593324818, 18163455439700846, 206235616589902956

Offset

1,2

Comments

Column 4 of A230614

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -45*a(n-2) +42*a(n-3) -12*a(n-4) +a(n-5).

Empirical: G.f. -2*x^2*(1-6*x^2+x^3) / ( (x-1)*(x^4-11*x^3+31*x^2-14*x+1) ). - R. J. Mathar, Oct 27 2013

Example

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

Crossrefs

Sequence in context: A277660 A089433 A152277 * A231597 A216119 A083446

Adjacent sequences: A230607 A230608 A230609 * A230611 A230612 A230613

Keyword

nonn

Author

R. H. Hardin, Oct 25 2013

Status

approved