a(n) = prime(n)-n*tau(n) where tau(n) is the number of divisors of n.

Terms

a(0) =1a(1) =-1a(2) =-1a(3) =-5a(4) =1a(5) =-11a(6) =3a(7) =-13a(8) =-4a(9) =-11a(10) =9a(11) =-35a(12) =15a(13) =-13a(14) =-13a(15) =-27a(16) =25a(17) =-47a(18) =29a(19) =-49a(20) =-11a(21) =-9a(22) =37a(23) =-103a(24) =22a(25) =-3a(26) =-5a(27) =-61a(28) =51a(29) =-127