A164758 Number of nX6 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 2 neighbors with the same value

83, 644, 2570, 6742, 13654, 24738

Offset

2,1

Links

Table of n, a(n) for n=2..7.

Example

Some solutions for n=3
...1.1.3.3.2.2...1.1.1.1.2.2...1.1.3.3.2.2...1.2.2.2.2.2...1.1.1.1.2.2
...3.1.1.3.4.2...3.3.3.1.2.4...3.1.1.3.4.4...1.2.4.4.4.4...3.3.3.3.3.3
...3.3.3.3.4.4...3.4.4.4.4.4...3.3.3.3.4.4...3.3.3.3.3.4...3.4.4.4.4.4
------
...1.1.1.1.2.2...1.1.1.1.2.2...1.1.1.1.1.2...1.2.2.2.2.2...1.3.3.4.2.2
...3.2.2.2.2.4...3.2.2.2.2.4...1.3.3.3.3.3...1.1.1.1.1.4...1.1.3.4.2.2
...3.3.3.4.4.4...3.3.3.3.4.4...3.3.4.4.4.4...3.3.4.4.4.4...3.3.3.4.4.4

Crossrefs

Sequence in context: A232887 A232884 A142289 * A142751 A176633 A059236

Adjacent sequences: A164755 A164756 A164757 * A164759 A164760 A164761

Keyword

nonn

Author

R. H. Hardin Aug 24 2009

Status

approved