The bottom entry in the difference table of the divisors of n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =4a(5) =2a(6) =6a(7) =1a(8) =4a(9) =0a(10) =10a(11) =1a(12) =12a(13) =-2a(14) =8a(15) =1a(16) =16a(17) =12a(18) =18a(19) =-11a(20) =8a(21) =-6a(22) =22a(23) =-12a(24) =16a(25) =-8a(26) =8a(27) =-3a(28) =28a(29) =50