a(n) = n + prime(n+1).

Terms

a(0) =4a(1) =7a(2) =10a(3) =15a(4) =18a(5) =23a(6) =26a(7) =31a(8) =38a(9) =41a(10) =48a(11) =53a(12) =56a(13) =61a(14) =68a(15) =75a(16) =78a(17) =85a(18) =90a(19) =93a(20) =100a(21) =105a(22) =112a(23) =121a(24) =126a(25) =129a(26) =134a(27) =137a(28) =142a(29) =157