Deficiency of n, or 2n - (sum of divisors of n).

Terms

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