a(n) = lcm_{k=1..n} (lcm(n,n-1,...,n-k+2,n-k+1)/lcm(1,2,...,k)).

Terms

a(0) =1a(1) =2a(2) =3a(3) =12a(4) =10a(5) =30a(6) =105a(7) =280a(8) =252a(9) =1260a(10) =2310a(11) =4620a(12) =4290a(13) =6006a(14) =15015a(15) =240240a(16) =680680a(17) =6126120a(18) =11639628a(19) =2771340a(20) =1763580a(21) =19399380a(22) =223092870a(23) =178474296a(24) =171609900a(25) =743642900a(26) =1434168450a(27) =20078358300a(28) =19409079690a(29) =19409079690