login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A265664
Number of 3Xn arrays containing n copies of 0..3-1 with no element plus any horizontal or vertical neighbor equal to 3-1.
1
2, 0, 4, 16, 60, 228, 1024, 4288, 18172, 76838, 326264, 1390048, 5947760, 25515274, 109801760, 473895774, 2050771696, 8896415264, 38680996104, 168532976250, 735715851956, 3217440736916, 14093823129980, 61831989407076
OFFSET
1,1
COMMENTS
Row 3 of A265663.
LINKS
EXAMPLE
Some solutions for n=4
..0..0..0..1....0..1..0..0....2..2..2..1....2..2..1..0....1..0..1..2
..1..0..1..2....1..2..1..0....1..2..1..0....2..1..0..0....0..1..2..2
..2..1..2..2....2..2..2..1....0..1..0..0....1..2..1..0....0..0..1..2
CROSSREFS
Cf. A265663.
Sequence in context: A320491 A295907 A317364 * A320490 A374401 A326215
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 12 2015
STATUS
approved