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A266826
Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north, west, northwest or southwest neighbor modulo 3 and the upper left element equal to 0.
1
1, 0, 1, 4, 10, 25, 45, 120, 399, 1108, 2923, 7991, 21953, 61747, 176646, 499952, 1409762, 3999661, 11391786, 32574598, 93459471, 268336007, 771070140, 2219952037, 6403510478, 18502345737, 53538515559, 155090741041, 449731074131
OFFSET
1,4
COMMENTS
Row 3 of A266825.
LINKS
EXAMPLE
All solutions for n=4
..0..2..1..1....0..2..2..1....0..0..2..1....0..2..1..0
..0..2..1..0....0..2..1..1....0..2..2..1....2..2..1..0
..2..2..1..0....0..2..1..0....0..2..1..1....2..1..1..0
CROSSREFS
Cf. A266825.
Sequence in context: A111153 A265438 A145368 * A111207 A298018 A254233
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 04 2016
STATUS
approved