A266826 - OEIS

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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, 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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

COMMENTS

Row 3 of A266825.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..105

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