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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, 4 in the lower right corner, and with no element having more than 3 neighbors with the same value
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%I #3 Mar 31 2012 12:35:35

%S 13,0,11588,110364,4185118,113675050,3445935988

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

%e One solution for n=7

%e ...1.1.2.2.2.2.2..............

%e .....1.1.1.1.2.2.2............

%e .......2.2.2.2.3.2.3..........

%e .........2.2.3.3.2.3.3........

%e ...........2.3.3.2.3.3.4......

%e .............3.3.2.3.4.4.4....

%e ...............3.3.3.3.3.4.4..

%e .................3.4.4.4.4.4.4

%K nonn

%O 2,1

%A _R. H. Hardin_ Sep 17 2009