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%I #2 Mar 31 2012 12:35:48
%S 1,0,2,6,20,90,550,3512,25378,200558,1778156,17016488,177741892,
%T 1984308356,23873823014,304944376412,4155112842840
%N Number of permutations of 2..n+1 with no element greater than or equal to the sum of its neighbors
%e All solutions for n=5
%e (2 3 4 6 5) (2 3 5 6 4) (2 3 6 5 4) (2 4 3 6 5)
%e (2 4 5 6 3) (2 4 6 5 3) (2 5 4 6 3) (2 5 6 4 3)
%e (2 6 5 4 3) (3 4 2 6 5) (3 4 5 6 2) (3 4 6 5 2)
%e (3 5 6 4 2) (3 6 4 5 2) (3 6 5 4 2) (4 5 6 3 2)
%e (4 6 5 3 2) (5 6 2 4 3) (5 6 3 4 2) (5 6 4 3 2)
%K nonn
%O 1,3
%A _R. H. Hardin_ Sep 23 2010
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