(2^p-(p+2))/p as p runs through the primes.

Terms

a(0) =0a(1) =1a(2) =5a(3) =17a(4) =185a(5) =629a(6) =7709a(7) =27593a(8) =364721a(9) =18512789a(10) =69273665a(11) =3714566309a(12) =53634713549a(13) =204560302841