A230615 Number of 3Xn 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, 0, 0, 30, 260, 2358, 20430, 176774, 1527918, 13204026, 114099558, 985963206, 8519922122, 73622499446, 636187953758, 5497437822074, 47504550336526, 410497104019406, 3547194348471034, 30652074338152030, 264871210587660230

Offset

1,4

Comments

Row 3 of A230614

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -64*a(n-2) +61*a(n-3) +181*a(n-4) -210*a(n-5) -679*a(n-6) +577*a(n-7) +2166*a(n-8) -2571*a(n-9) -789*a(n-10) +760*a(n-11) +618*a(n-12) +264*a(n-13) +56*a(n-14) for n>17

Example

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

Crossrefs

Sequence in context: A024448 A125367 A126525 * A230731 A053358 A163667

Adjacent sequences: A230612 A230613 A230614 * A230616 A230617 A230618

Keyword

nonn

Author

R. H. Hardin, Oct 25 2013

Status

approved