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%I #3 Mar 31 2012 12:35:35
%S 7,40,2467,18900,174197,1357468,9996371,68364692,445699471,2796474838,
%T 16994094852
%N Number of slanted 5Xn (i=1..5)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 Some 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 .......2.2.2...........1.1.1...........2.3.3...........1.1.1....
%e .........4.4.4...........3.3.3...........3.3.4...........3.3.4..
%e ...........3.4.4...........3.3.4...........3.4.4...........3.4.4
%e ------
%e ...1.1.2...........1.2.2...........1.2.2...........1.1.2........
%e .....1.1.1...........2.2.2...........2.2.2...........1.2.2......
%e .......1.4.4...........3.3.3...........4.4.4...........3.3.3....
%e .........4.4.4...........3.3.4...........4.4.4...........3.3.4..
%e ...........3.4.4...........3.4.4...........3.4.4...........3.4.4
%e ------
%e ...1.1.2...........1.1.2...........1.1.2...........1.2.2........
%e .....1.2.2...........1.2.4...........1.1.4...........2.2.4......
%e .......2.2.3...........2.4.4...........1.4.4...........2.4.4....
%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
%K nonn
%O 2,1
%A _R. H. Hardin_ Sep 17 2009
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