%I #3 Mar 31 2012 12:35:44
%S 1,25,3500,1348025,1752218300,5398931034000,22475921070676500
%N Number of permutations of 4 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/6)] (6-way heap)
%Y Simple 2-way heap A056971
%K nonn
%O 1,2
%A _R. H. Hardin_ May 17 2010