a(n) = lcm{1,2,...,n} / binomial(n,floor(n/2)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =6a(6) =3a(7) =12a(8) =12a(9) =20a(10) =10a(11) =60a(12) =30a(13) =210a(14) =105a(15) =56a(16) =56a(17) =504a(18) =252a(19) =2520a(20) =1260a(21) =660a(22) =330a(23) =3960a(24) =1980a(25) =5148a(26) =2574a(27) =4004a(28) =2002a(29) =30030