a(n) = Sum_{i=n+1..2n} prime(i) - Sum_{i=1..n} prime(i).

Terms

a(0) =1a(1) =7a(2) =21a(3) =43a(4) =73a(5) =115a(6) =165a(7) =227a(8) =301a(9) =381a(10) =471a(11) =569a(12) =685a(13) =809a(14) =937a(15) =1089a(16) =1247a(17) =1425a(18) =1611a(19) =1809a(20) =2023a(21) =2249a(22) =2479a(23) =2735a(24) =2997a(25) =3267a(26) =3553a(27) =3859a(28) =4181a(29) =4513