A165391 Number of slanted 8Xn (i=1..8)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

13, 360, 45585, 3239860, 182659489, 8713467416, 397609974217

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..............
.....1.1.2.2.2.2.2.2............
.......1.1.2.2.3.3.2.2..........
.........1.2.3.3.3.3.2.2........
...........3.3.3.3.3.3.3.4......
.............3.3.3.3.3.4.4.4....
...............3.3.3.4.4.4.4.4..
.................3.3.3.3.3.3.4.4

Crossrefs

Sequence in context: A220636 A078738 A218419 * A061015 A330255 A280796

Adjacent sequences: A165388 A165389 A165390 * A165392 A165393 A165394

Keyword

nonn

Author

R. H. Hardin Sep 17 2009

Status

approved