a(n) = (-1)^n*prime(n).

Terms

a(0) =-2a(1) =3a(2) =-5a(3) =7a(4) =-11a(5) =13a(6) =-17a(7) =19a(8) =-23a(9) =29a(10) =-31a(11) =37a(12) =-41a(13) =43a(14) =-47a(15) =53a(16) =-59a(17) =61a(18) =-67a(19) =71a(20) =-73a(21) =79a(22) =-83a(23) =89a(24) =-97a(25) =101a(26) =-103a(27) =107a(28) =-109a(29) =113