a(0) = 0, a(n+1) = a(n) + next prime larger than a(n).

Terms

a(0) =0a(1) =2a(2) =5a(3) =12a(4) =25a(5) =54a(6) =113a(7) =240a(8) =481a(9) =968a(10) =1939a(11) =3888a(12) =7777a(13) =15566a(14) =31135a(15) =62274a(16) =124571a(17) =249148a(18) =498329a(19) =996660a(20) =1993349a(21) =3986706a(22) =7973417a(23) =15946836a(24) =31893677a(25) =63787390a(26) =127574781a(27) =255149570a(28) =510299161a(29) =1020598332