A165388 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, and 4 in the lower right corner

7, 168, 4569, 63740, 755947, 7834644, 74493401, 661071448, 5551999772, 44577303412

Offset

2,1

Links

Table of n, a(n) for n=2..11.

Example

Some solutions for n=3
...1.2.2...........1.1.2...........1.1.2...........1.1.2........
.....2.2.2...........1.1.1...........1.2.4...........1.1.1......
.......2.2.2...........1.3.3...........4.4.4...........1.4.4....
.........2.3.4...........3.3.3...........4.4.4...........4.4.4..
...........3.4.4...........3.4.4...........3.4.4...........3.4.4
------
...1.1.2...........1.1.2...........1.1.2...........1.1.2........
.....1.2.2...........2.2.2...........1.1.1...........1.1.1......
.......2.2.3...........2.2.3...........1.1.1...........1.1.3....
.........2.3.4...........3.3.4...........1.3.3...........1.3.4..
...........3.4.4...........3.4.4...........3.4.4...........3.4.4
------
...1.3.2...........1.1.2...........1.2.2...........1.1.2........
.....3.3.3...........1.1.1...........2.2.2...........1.1.1......
.......3.3.3...........3.3.3...........4.4.4...........1.1.1....
.........3.3.3...........3.3.4...........4.4.4...........4.4.4..
...........3.4.4...........3.4.4...........3.4.4...........3.4.4

Crossrefs

Sequence in context: A192275 A009807 A220991 * A124126 A086373 A162131

Adjacent sequences: A165385 A165386 A165387 * A165389 A165390 A165391

Keyword

nonn

Author

R. H. Hardin Sep 17 2009

Status

approved