%I
%S 1,1,2,3,12,10,30,105,56,252,1260,330,1980,2574,2002,15015,240240,
%T 61880,15912,151164,38760,406980,4476780,1144066,13728792,24515700,
%U 6249100,84362850,21474180,5462730,81940950,1270084725,645122400
%N a(n) = lcm{1, ..., 2n} / binomial(2n, n).
%C Known to be always an integer.
%H Hojoo Lee, <a href="https://listserv.nodak.edu/cgibin/wa.exe?A2=NMBRTHRY;2e3bb004.0202">Re: LCM [1,2,..,N] > 2^{N1}</a>, NMBRTHRY Mailing List, Feb 18 2002.
%F a(n) = A099996(n) / A000984(n) = A003418(2*n) / A001405(2*n) = A180000(2*n) = A263673(2*n).
%F a(n) = n * A068553(n) = n * A048619(2*n1).
%Y Bisection of A180000 and A263673.
%K nonn,easy
%O 0,3
%A _N. J. A. Sloane_, Mar 23 2002
%E a(0)=1 prepended by _Max Alekseyev_, Oct 23 2015
