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A210303
Number of (n+1)X3 0..3 arrays containing all values 0..3 with every 2X2 subblock having one or three distinct values, and new values 0..3 introduced in row major order
1
29, 1091, 27957, 655743, 14976529, 339125187, 7657326365, 172736626311, 3895426271881, 87837486236459, 1980567115521301, 44657472344530991, 1006924739685862081, 22703839965026573971, 511919216667906316429
OFFSET
1,1
COMMENTS
Column 2 of A210309
LINKS
FORMULA
Empirical: a(n) = 35*a(n-1) -315*a(n-2) +729*a(n-3) +1132*a(n-4) -3804*a(n-5) +688*a(n-6) +1536*a(n-7)
EXAMPLE
Some solutions for n=4
..0..0..0....0..0..1....0..1..0....0..0..1....0..1..0....0..0..0....0..1..0
..0..0..0....1..2..0....0..2..1....1..2..2....0..2..0....0..0..0....2..0..2
..1..2..1....2..3..2....1..1..3....0..0..1....2..3..2....1..2..3....0..3..0
..0..1..3....0..3..0....2..3..0....0..0..2....1..1..1....0..1..1....1..3..1
..1..3..0....2..0..2....1..1..1....1..2..3....3..0..2....0..2..0....3..0..0
CROSSREFS
Sequence in context: A138660 A237356 A176695 * A268461 A025761 A003735
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 19 2012
STATUS
approved