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A233100
Number of 3 X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order.
1
10, 74, 941, 11486, 141566, 1742447, 21452183, 264098522, 3251348462, 40027693247, 492785243519, 6066732018746, 74688189381254, 919494319284479, 11319993299254919, 139361653035025178, 1715696275016282462
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 13*a(n-1) - 5*a(n-2) - 47*a(n-3) + 52*a(n-4) - 12*a(n-5) for n>6.
Empirical g.f.: x*(10 - 56*x + 29*x^2 + 93*x^3 - 89*x^4 + 18*x^5) / ((1 - x)*(1 - 12*x - 7*x^2 + 40*x^3 - 12*x^4)). - Colin Barker, Oct 07 2018
EXAMPLE
Some solutions for n=4:
..0..1..1..1....0..1..0..1....0..1..1..3....0..1..3..1....0..0..0..0
..0..0..0..0....0..0..1..1....3..1..3..1....1..1..3..2....0..0..1..1
..1..0..0..2....0..1..1..3....1..3..1..3....3..1..3..3....1..1..1..3
CROSSREFS
Row 3 of A233098.
Sequence in context: A264082 A103434 A119167 * A266674 A233455 A027778
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 04 2013
STATUS
approved