a(1) = 1, a(n) = lcm(n, a(n-1)) / gcd(n, a(n-1)).

Terms

a(0) =1a(1) =2a(2) =6a(3) =6a(4) =30a(5) =5a(6) =35a(7) =280a(8) =2520a(9) =252a(10) =2772a(11) =231a(12) =3003a(13) =858a(14) =1430a(15) =5720a(16) =97240a(17) =437580a(18) =8314020a(19) =415701a(20) =969969a(21) =176358a(22) =4056234a(23) =2704156a(24) =67603900a(25) =2600150a(26) =70204050a(27) =10029150a(28) =290845350a(29) =9694845