A164753 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 2 neighbors with the same value

1, 80, 739, 3496, 13654

Offset

2,2

Links

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

Example

Some solutions for n=4
...1.1.1.2...1.2.2.2...1.1.1.2...1.1.2.2...1.3.2.2...1.1.1.2...1.1.2.2
...1.4.4.2...1.1.4.4...1.2.2.2...3.1.2.4...1.3.2.4...1.2.2.2...3.1.4.2
...1.3.4.2...3.1.1.4...1.1.3.3...3.1.1.4...3.3.2.4...1.3.3.3...3.1.4.2
...3.3.4.4...3.3.3.4...3.3.3.4...3.3.3.4...3.4.4.4...3.3.4.4...3.1.4.4
------
...1.2.2.2...1.1.1.2...1.2.2.2...1.1.2.2...1.3.2.2...1.1.2.2...1.4.2.2
...1.1.1.4...1.3.1.2...1.4.4.4...1.2.2.3...1.3.4.2...1.4.4.2...3.4.2.2
...3.4.1.4...3.3.1.1...1.1.1.4...2.2.3.3...1.3.4.2...3.4.2.2...3.4.4.4
...3.4.4.4...3.4.4.4...3.3.4.4...3.3.3.4...3.3.4.4...3.4.4.4...3.3.3.4

Crossrefs

Sequence in context: A204342 A235090 A211693 * A279745 A062911 A024392

Adjacent sequences: A164750 A164751 A164752 * A164754 A164755 A164756

Keyword

nonn

Author

R. H. Hardin Aug 24 2009

Status

approved