A164757 Number of nX5 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

50, 480, 1538, 3496, 6742, 10476, 14432, 18120, 21386

Offset

2,1

Links

Table of n, a(n) for n=2..10.

Example

Some solutions for n=3
...1.1.1.2.2...1.4.4.2.2...1.1.1.1.2...1.1.2.2.2...1.1.1.3.2...1.1.2.2.2
...1.3.3.2.2...3.3.4.2.4...1.3.3.1.1...3.2.2.3.2...1.3.3.3.2...3.1.1.1.1
...3.3.4.4.4...3.3.4.4.4...3.3.4.4.4...3.3.3.3.4...3.3.4.4.4...3.3.3.3.4
------
...1.4.2.2.2...1.1.2.2.2...1.1.3.2.2...1.1.1.2.2...1.1.1.1.2...1.1.3.2.2
...3.4.4.4.2...1.1.2.4.4...1.3.3.2.4...3.3.3.2.4...1.2.2.2.2...3.1.3.2.2
...3.3.3.4.4...3.3.2.2.4...3.3.4.4.4...3.2.2.2.4...3.2.4.4.4...3.3.3.4.4

Crossrefs

Sequence in context: A222693 A228743 A019561 * A189415 A128954 A022147

Adjacent sequences: A164754 A164755 A164756 * A164758 A164759 A164760

Keyword

nonn

Author

R. H. Hardin Aug 24 2009

Status

approved