Sum of first 2n primes.

Terms

a(0) =0a(1) =5a(2) =17a(3) =41a(4) =77a(5) =129a(6) =197a(7) =281a(8) =381a(9) =501a(10) =639a(11) =791a(12) =963a(13) =1161a(14) =1371a(15) =1593a(16) =1851a(17) =2127a(18) =2427a(19) =2747a(20) =3087a(21) =3447a(22) =3831a(23) =4227a(24) =4661a(25) =5117a(26) =5589a(27) =6081a(28) =6601a(29) =7141