A231109 Number of 3Xn 0..3 arrays x(i,j) with each element horizontally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero

0, 0, 8, 48, 286, 1748, 10734, 65934, 404984, 2487534, 15279170, 93849326, 576451382, 3540741892, 21748327444, 133584927368, 820519778376, 5039885260498, 30956527928058, 190144531428150, 1167926290556226

Offset

1,3

Comments

Row 3 of A231108

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -26*a(n-2) +6*a(n-3) +60*a(n-4) -56*a(n-5) -38*a(n-6) +54*a(n-7) -9*a(n-8) +18*a(n-9) -20*a(n-10) +2*a(n-12) for n>16

Example

Some solutions for n=4
..0..1..0..1....0..1..2..1....0..1..2..3....0..1..0..3....0..1..2..0
..2..3..2..1....0..3..2..1....0..1..0..1....2..3..2..3....0..3..1..2
..2..3..0..3....2..3..0..3....0..3..2..1....0..1..0..3....2..0..3..2

Crossrefs

Sequence in context: A295047 A295375 A081554 * A079743 A079765 A079744

Adjacent sequences: A231106 A231107 A231108 * A231110 A231111 A231112

Keyword

nonn

Author

R. H. Hardin, Nov 03 2013

Status

approved