Product(n/k - k) where the product is over the divisors k of n and where 1 <= k <= sqrt(n).

Terms

a(0) =0a(1) =1a(2) =2a(3) =0a(4) =4a(5) =5a(6) =6a(7) =14a(8) =0a(9) =27a(10) =10a(11) =44a(12) =12a(13) =65a(14) =28a(15) =0a(16) =16a(17) =357a(18) =18a(19) =152a(20) =80a(21) =189a(22) =22a(23) =2300a(24) =0a(25) =275a(26) =156a(27) =972a(28) =28a(29) =2639