a(n) = product of numbers k < n such that 1 < gcd(k,n) and rad(k) != rad(n).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =24a(6) =1a(7) =6a(8) =6a(9) =1920a(10) =1a(11) =17280a(12) =1a(13) =322560a(14) =97200a(15) =10080a(16) =1a(17) =58060800a(18) =1a(19) =1393459200a(20) =51438240a(21) =40874803200a(22) =1a(23) =536481792000a(24) =3000a(26) =9797760a(28) =1a(30) =1