a(n) = LCM { sigma(1), ..., sigma(n) }.

Terms

a(0) =1a(1) =1a(2) =3a(3) =12a(4) =84a(5) =84a(6) =84a(7) =168a(8) =840a(9) =10920a(10) =32760a(11) =32760a(12) =32760a(13) =32760a(14) =32760a(15) =32760a(16) =1015560a(17) =1015560a(18) =1015560a(19) =1015560a(20) =1015560a(21) =4062240a(22) =4062240a(23) =4062240a(24) =4062240a(25) =4062240a(26) =4062240a(27) =4062240a(28) =4062240a(29) =4062240