Start with 0, run through primes >=5, adding if -1 mod 6, subtracting if +1 mod 6.

Terms

a(0) =0a(1) =5a(2) =-2a(3) =9a(4) =-4a(5) =13a(6) =-6a(7) =17a(8) =46a(9) =15a(10) =-22a(11) =19a(12) =-24a(13) =23a(14) =76a(15) =135a(16) =74a(17) =7a(18) =78a(19) =5a(20) =-74a(21) =9a(22) =98a(23) =1a(24) =102a(25) =-1a(26) =106a(27) =-3a(28) =110a(29) =-17