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A164761
Number of nX4 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 3 neighbors with the same value
0
33, 670, 6549, 45892, 265155, 1347918, 6257643, 27154502, 111837041, 441803872, 1686870551, 6260508940, 22683215853, 80510078988, 280693737065, 963421173780, 3261335507803, 10905208348554
OFFSET
2,1
EXAMPLE
Some solutions for n=3
...1.1.2.2...1.1.2.2...1.1.1.2...1.3.4.2...1.1.1.2...1.1.2.2...1.1.2.2
...1.1.3.4...1.4.4.4...3.4.1.1...3.3.4.4...3.3.4.4...3.3.3.2...3.1.2.2
...3.3.3.4...3.4.4.4...3.4.4.4...3.3.3.4...3.4.4.4...3.4.4.4...3.1.1.4
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...1.4.4.2...1.4.2.2...1.2.2.2...1.2.2.2...1.1.1.2...1.1.2.2...1.1.2.2
...1.1.4.4...3.4.4.4...1.1.2.4...1.2.2.4...1.3.1.4...3.1.2.2...2.2.2.4
...3.3.4.4...3.3.4.4...3.3.4.4...3.4.4.4...3.3.4.4...3.1.2.4...3.4.4.4
CROSSREFS
Sequence in context: A094760 A365645 A083956 * A028210 A028205 A028191
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 24 2009
STATUS
approved