%I #5 Mar 30 2012 18:38:56
%S 1,4,36,144,3600,3600,176400,705600,6350400,31752000,3841992000,
%T 3841992000,649296648000,649296648000,129859329600,519437318400,
%U 150117385017600,150117385017600,54192375991353600,270961879956768000
%N Denominator(sum(i=1,n,1/i^4))/denominator(sum(i=1,n,1/i^2)).
%K easy,nonn
%O 1,2
%A _Benoit Cloitre_, Apr 03 2002