A230471 Number of 3Xn 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero

0, 2, 114, 2398, 35052, 552720, 8724560, 138661614, 2199713318, 34899147754, 553614141632, 8782488190400, 139324085002332, 2210222301992486, 35062696826816334, 556230414443092114, 8823972052874445168

Offset

1,2

Comments

Row 3 of A230469

Links

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

Formula

Empirical: a(n) = 14*a(n-1) +28*a(n-2) -48*a(n-3) +1092*a(n-4) +977*a(n-5) +713*a(n-6) -890*a(n-7) -1936*a(n-8) -2762*a(n-9) -712*a(n-10) -1021*a(n-11) -128*a(n-12) -438*a(n-13) -24*a(n-15) +16*a(n-16) for n>17

Example

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

Crossrefs

Sequence in context: A217088 A034312 A224871 * A140986 A157068 A008271

Adjacent sequences: A230468 A230469 A230470 * A230472 A230473 A230474

Keyword

nonn

Author

R. H. Hardin, Oct 20 2013

Status

approved