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A164759 Number of n X n 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
1, 104, 6549, 492920, 63388030 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Table of n, a(n) for n=2..6.

EXAMPLE

Some solutions for n=4

...1.1.2.2...1.4.4.2...1.1.3.2...1.1.2.2...1.1.2.2...1.1.2.2...1.1.1.2

...3.1.2.4...1.1.4.2...1.1.3.2...3.1.2.2...1.1.2.2...1.3.2.2...1.3.1.2

...3.3.2.4...1.3.4.2...3.3.3.2...3.1.2.4...1.4.4.2...3.3.3.4...3.3.1.2

...3.3.4.4...3.3.4.4...3.3.4.4...3.1.2.4...3.3.4.4...3.4.4.4...3.1.1.4

------

...1.2.2.2...1.4.4.2...1.2.2.2...1.2.2.2...1.1.2.2...1.2.2.2...1.1.2.2

...1.2.3.2...1.4.4.2...1.3.2.2...1.1.2.4...1.3.3.2...1.1.1.1...1.2.2.2

...3.3.3.3...3.4.4.2...3.3.2.2...1.3.4.4...1.3.3.3...3.1.1.4...1.2.4.4

...3.4.4.4...3.3.4.4...3.3.2.4...3.3.3.4...3.3.4.4...3.3.4.4...3.2.4.4

CROSSREFS

Sequence in context: A035811 A004393 A286329 * A206013 A187700 A015272

Adjacent sequences:  A164756 A164757 A164758 * A164760 A164761 A164762

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 24 2009

STATUS

approved

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Last modified February 27 19:23 EST 2020. Contains 332308 sequences. (Running on oeis4.)