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A232363
Number of n X 3 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or vertically.
1
7, 145, 2411, 39321, 647287, 10652849, 175284259, 2884208601, 47458332799, 780904692697, 12849420860335, 211431203704621, 3479001459520535, 57245340037605157, 941945266264605543, 15499268308326369925
OFFSET
1,1
COMMENTS
Column 3 of A232368.
LINKS
FORMULA
Empirical: a(n) = 15*a(n-1) +13*a(n-2) +171*a(n-3) +144*a(n-4) +128*a(n-5) -1072*a(n-6) -5144*a(n-7) -6575*a(n-8) -1670*a(n-9) +29979*a(n-10) +28328*a(n-11) -17313*a(n-12) -16033*a(n-13) -7412*a(n-14) -6950*a(n-15) +6052*a(n-16) +6881*a(n-17) +4681*a(n-18) +3057*a(n-19) +575*a(n-20) +420*a(n-21).
EXAMPLE
Some solutions for n=4
..1..2..1....1..2..1....0..1..2....1..0..2....0..2..2....0..1..2....1..0..0
..2..2..1....2..1..0....2..0..1....2..1..1....1..2..1....2..2..1....2..2..1
..0..1..0....2..0..2....2..1..2....1..0..1....0..1..0....1..2..1....2..2..1
..1..2..1....2..1..0....2..0..1....1..2..2....1..2..2....2..2..2....2..1..0
CROSSREFS
Cf. A232368.
Sequence in context: A367527 A296684 A012826 * A102059 A064624 A342113
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 23 2013
STATUS
approved