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A230933
Number of black-square subarrays of (n+2)X(6+2) 0..3 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero
2
42, 438, 3768, 37984, 396950, 4092246, 41991510, 431437274, 4435310118, 45590703272, 468598417126, 4816515719528, 49507271980530, 508867096276696, 5230454214732138, 53761897206996568, 552598679075230458
OFFSET
1,1
COMMENTS
Column 6 of A230935
FORMULA
Empirical recurrence of order 71 (see link above)
EXAMPLE
Some solutions for n=4
..x..0..x..0..x..1..x..3....x..0..x..2..x..2..x..0....x..0..x..2..x..0..x..0
..3..x..1..x..2..x..0..x....1..x..3..x..3..x..1..x....3..x..1..x..3..x..1..x
..x..2..x..0..x..3..x..1....x..2..x..0..x..0..x..0....x..2..x..0..x..2..x..0
..1..x..3..x..1..x..2..x....1..x..3..x..1..x..3..x....1..x..1..x..1..x..3..x
..x..0..x..2..x..0..x..1....x..2..x..2..x..0..x..2....x..0..x..0..x..0..x..2
..3..x..3..x..3..x..3..x....1..x..1..x..3..x..3..x....3..x..3..x..3..x..3..x
CROSSREFS
Sequence in context: A251425 A242144 A242145 * A231110 A156762 A248094
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 01 2013
STATUS
approved