a(n) is the index of the smallest prime such that the gap to the next prime is not less than 2*n.

Terms

a(0) =2a(1) =4a(2) =9a(3) =24a(4) =30a(5) =30a(6) =30a(7) =99a(8) =99a(9) =154a(10) =189a(11) =217a(12) =217a(13) =217a(14) =217a(15) =217a(16) =217a(17) =1183a(18) =1831a(19) =1831a(20) =1831a(21) =1831a(22) =2225a(23) =2225a(24) =2225a(25) =2225a(26) =3385a(27) =3385a(28) =3385a(29) =3385