a(n) = Sum_{k=1..n} prime(k) * s(k), where s(k) = (-1)^(floor(k/2)).

Terms

a(0) =2a(1) =-1a(2) =-6a(3) =1a(4) =12a(5) =-1a(6) =-18a(7) =1a(8) =24a(9) =-5a(10) =-36a(11) =1a(12) =42a(13) =-1a(14) =-48a(15) =5a(16) =64a(17) =3a(18) =-64a(19) =7a(20) =80a(21) =1a(22) =-82a(23) =7a(24) =104a(25) =3a(26) =-100a(27) =7a(28) =116a(29) =3