a(0) = 1; a(n) = LCM(n, sum{k=0 to n-1}[a(k)]).

Terms

a(0) =1a(1) =1a(2) =2a(3) =12a(4) =16a(5) =160a(6) =192a(7) =2688a(8) =3072a(9) =18432a(10) =122880a(11) =1622016a(12) =1769472a(13) =46006272a(14) =49545216a(15) =495452160a(16) =594542592a(17) =20214448128a(18) =21403533312a(19) =813334265856a(20) =856141332480