A165397 Number of slanted 5Xn (i=1..5)X(j=i..n+i-1) 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

7, 40, 2467, 18900, 174197, 1357468, 9996371, 68364692, 445699471, 2796474838, 16994094852

Offset

2,1

Links

Table of n, a(n) for n=2..12.

Example

Some solutions for n=3
...1.1.2...........1.1.2...........1.1.2...........1.1.2........
.....1.2.2...........1.1.1...........1.2.2...........1.1.1......
.......2.2.2...........1.1.1...........2.3.3...........1.1.1....
.........4.4.4...........3.3.3...........3.3.4...........3.3.4..
...........3.4.4...........3.3.4...........3.4.4...........3.4.4
------
...1.1.2...........1.2.2...........1.2.2...........1.1.2........
.....1.1.1...........2.2.2...........2.2.2...........1.2.2......
.......1.4.4...........3.3.3...........4.4.4...........3.3.3....
.........4.4.4...........3.3.4...........4.4.4...........3.3.4..
...........3.4.4...........3.4.4...........3.4.4...........3.4.4
------
...1.1.2...........1.1.2...........1.1.2...........1.2.2........
.....1.2.2...........1.2.4...........1.1.4...........2.2.4......
.......2.2.3...........2.4.4...........1.4.4...........2.4.4....
.........3.3.4...........4.4.4...........4.4.4...........4.4.4..
...........3.4.4...........3.4.4...........3.4.4...........3.4.4

Crossrefs

Sequence in context: A356046 A062727 A223416 * A123747 A144421 A023251

Adjacent sequences: A165394 A165395 A165396 * A165398 A165399 A165400

Keyword

nonn

Author

R. H. Hardin Sep 17 2009

Status

approved