A165389 Number of slanted 6Xn (i=1..6)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

9, 232, 11449, 272548, 5386897, 92769304, 1484483677, 22335647312, 319719142737

Offset

2,1

Links

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

Example

Some solutions for n=3
...1.2.2.............1.1.2.............1.1.2.............1.1.2..........
.....2.2.2.............1.1.1.............2.2.2.............2.2.2........
.......2.2.2.............1.1.1.............2.2.2.............2.2.3......
.........2.2.2.............1.4.4.............2.2.2.............2.3.3....
...........2.3.3.............4.4.4.............3.3.3.............3.3.3..
.............3.4.4.............3.4.4.............3.3.4.............3.4.4
------
...1.1.2.............1.1.2.............1.1.2.............1.1.2..........
.....2.2.2.............2.2.2.............1.1.1.............2.2.2........
.......2.2.2.............2.2.2.............1.1.1.............2.2.2......
.........2.2.4.............2.2.3.............1.1.1.............2.4.4....
...........2.4.4.............2.3.3.............1.1.3.............4.4.4..
.............3.4.4.............3.4.4.............3.3.4.............3.4.4

Crossrefs

Sequence in context: A181205 A152101 A230178 * A153223 A276536 A288683

Adjacent sequences: A165386 A165387 A165388 * A165390 A165391 A165392

Keyword

nonn

Author

R. H. Hardin Sep 17 2009

Status

approved