%I #3 Mar 31 2012 12:35:18
%S 0,2,13485,2273540,167274075,8894295174,406137173897
%N Number of permutations of 4 indistinguishable copies of 1..n arranged in a circle with exactly 4 adjacent element pairs in decreasing order.
%K nonn
%O 1,2
%A _R. H. Hardin_ May 21 2009