A165398 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, 4 in the lower right corner, and with no element having more than 3 neighbors with the same value

9, 8, 4708, 40058, 598332, 7051772, 81612367, 869819150

Offset

2,1

Links

Table of n, a(n) for n=2..9.

Example

All solutions for n=3
...1.1.2.............1.1.2.............1.1.2.............1.1.2..........
.....1.2.2.............1.1.1.............1.2.2.............1.1.1........
.......2.2.3.............1.1.1.............2.2.2.............1.1.4......
.........2.3.3.............4.4.4.............4.4.4.............1.4.4....
...........3.3.4.............4.4.4.............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..........
.....1.1.1.............1.2.2.............1.1.1.............1.2.2........
.......1.1.1.............2.2.4.............1.1.3.............2.2.2......
.........3.3.3.............2.4.4.............1.3.3.............3.3.3....
...........3.3.4.............4.4.4.............3.3.4.............3.3.4..
.............3.4.4.............3.4.4.............3.4.4.............3.4.4

Crossrefs

Sequence in context: A038298 A013439 A180680 * A329716 A021105 A334711

Adjacent sequences: A165395 A165396 A165397 * A165399 A165400 A165401

Keyword

nonn

Author

R. H. Hardin Sep 17 2009

Status

approved