Sum of the first 2n+1 primes.

Terms

a(0) =2a(1) =10a(2) =28a(3) =58a(4) =100a(5) =160a(6) =238a(7) =328a(8) =440a(9) =568a(10) =712a(11) =874a(12) =1060a(13) =1264a(14) =1480a(15) =1720a(16) =1988a(17) =2276a(18) =2584a(19) =2914a(20) =3266a(21) =3638a(22) =4028a(23) =4438a(24) =4888a(25) =5350a(26) =5830a(27) =6338a(28) =6870a(29) =7418