a(1) = 1; thereafter a(n) is the product of all 0 < m < n for which a(m) divides n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =2a(5) =120a(6) =2a(7) =210a(8) =2a(9) =1890a(10) =2a(11) =83160a(12) =2a(13) =270270a(14) =2a(15) =4054050a(16) =2a(17) =275675400a(18) =2a(19) =1309458150a(20) =2a(21) =27498621150a(22) =2a(24) =2a(26) =2a(28) =2a(30) =2a(32) =2a(34) =2