a(n) = lcm(n, sigma(n)).

Terms

a(0) =1a(1) =6a(2) =12a(3) =28a(4) =30a(5) =12a(6) =56a(7) =120a(8) =117a(9) =90a(10) =132a(11) =84a(12) =182a(13) =168a(14) =120a(15) =496a(16) =306a(17) =234a(18) =380a(19) =420a(20) =672a(21) =396a(22) =552a(23) =120a(24) =775a(25) =546a(26) =1080a(27) =56a(28) =870a(29) =360