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A186556
Number of (n+1)X4 0..3 arrays with no 2X2 subblock commuting with any of its horizontal and vertical 2X2 subblock neighbors.
4
60074, 13360840, 2976803436, 663296784123, 147795682647630, 32931888185295104, 7337893459883784628, 1635031754050410331405, 364318292831600934919531, 81177517366244082982029095
OFFSET
1,1
COMMENTS
Column 3 of A186558
LINKS
EXAMPLE
Some solutions for 3X4
..2..3..0..0....0..1..2..3....3..3..1..2....1..1..3..0....2..3..1..2
..0..1..0..2....0..3..0..2....0..2..3..2....0..2..1..2....0..1..1..1
..0..0..0..2....0..0..0..2....0..0..3..0....0..0..1..3....0..0..2..3
CROSSREFS
Sequence in context: A287047 A384221 A075671 * A205983 A218488 A257754
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 23 2011
STATUS
approved