A165385 Number of slanted nX8 (i=1..n)X(j=i..8+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.

869, 59472, 927564, 9996371, 81612367, 564638514, 3445935988

Offset

2,1

Links

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

Example

One solution for n=7
...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: A250522 A251060 A205224 * A165377 A283449 A351878

Adjacent sequences: A165382 A165383 A165384 * A165386 A165387 A165388

Keyword

nonn

Author

R. H. Hardin, Sep 17 2009

Status

approved