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%I #2 Apr 30 2014 01:26:48
%S 3,11,26,154,684,5508,35664,361296,3068640,37383840,392722560,
%T 5584394880,69878833920,1135360800000,16484477184000,301158902016000,
%U 4976250951168000,100951141777920000,1870345490614272000
%N n! * Sum[k=floor(n/2)..n, 1/k].
%Y Cf. A101609, A101610, A101611, A101613, A000254, A046673, A052517.
%K nonn,easy
%O 2,1
%A _Ralf Stephan_, Dec 10 2004