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A206341 Number of (n+1)X7 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor 1
880, 1589, 2030, 4711, 6090, 14181, 18258, 42351, 54654, 126861, 163842, 380391, 491406, 1141143, 1474206, 3423417, 4422606, 10270239, 13267806, 30810705, 39803406, 92432103, 119410206, 277296297, 358230606, 831888879, 1074691806 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 6 of A206343
LINKS
FORMULA
Empirical: a(n) = a(n-1) +3*a(n-2) -3*a(n-3) for n>15
EXAMPLE
Some solutions for n=4
..0..1..0..1..0..2..0....1..0..1..0..1..0..1....3..3..0..2..0..2..0
..3..0..1..0..1..0..2....0..1..0..1..0..1..0....2..0..3..0..2..0..2
..0..3..0..1..0..1..0....1..0..1..0..1..0..1....0..2..0..3..0..2..0
..1..0..3..0..1..0..1....0..1..0..1..0..1..0....1..0..2..0..3..0..2
..0..1..0..3..0..1..1....1..0..1..0..1..0..1....0..1..0..2..0..3..1
CROSSREFS
Sequence in context: A190030 A118799 A050424 * A357495 A024393 A006052
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 06 2012
STATUS
approved

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Last modified April 21 22:37 EDT 2024. Contains 371886 sequences. (Running on oeis4.)