A165399 Number of slanted 7Xn (i=1..7)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

11, 0, 7748, 70658, 1700146, 30346872, 564638514

Offset

2,1

Links

Table of n, a(n) for n=2..8.

Example

One solution for n=8
...1.1.2.2.2.2.2.2............
.....1.1.2.2.2.3.2.2..........
.......1.2.3.2.3.2.2.2........
.........3.3.2.3.2.3.3.4......
...........3.3.3.2.3.4.4.4....
.............3.3.2.3.3.3.4.4..
...............3.3.3.3.3.3.4.4

Crossrefs

Sequence in context: A277560 A073865 A036931 * A157712 A266379 A158215

Adjacent sequences: A165396 A165397 A165398 * A165400 A165401 A165402

Keyword

nonn

Author

R. H. Hardin Sep 17 2009

Status

approved