%I #3 Mar 31 2012 12:35:35
%S 9,8,4708,40058,598332,7051772,81612367,869819150
%N 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
%e All solutions for n=3
%e ...1.1.2.............1.1.2.............1.1.2.............1.1.2..........
%e .....1.2.2.............1.1.1.............1.2.2.............1.1.1........
%e .......2.2.3.............1.1.1.............2.2.2.............1.1.4......
%e .........2.3.3.............4.4.4.............4.4.4.............1.4.4....
%e ...........3.3.4.............4.4.4.............4.4.4.............4.4.4..
%e .............3.4.4.............3.4.4.............3.4.4.............3.4.4
%e ------
%e ...1.1.2.............1.1.2.............1.1.2.............1.1.2..........
%e .....1.1.1.............1.2.2.............1.1.1.............1.2.2........
%e .......1.1.1.............2.2.4.............1.1.3.............2.2.2......
%e .........3.3.3.............2.4.4.............1.3.3.............3.3.3....
%e ...........3.3.4.............4.4.4.............3.3.4.............3.3.4..
%e .............3.4.4.............3.4.4.............3.4.4.............3.4.4
%K nonn
%O 2,1
%A _R. H. Hardin_ Sep 17 2009