(n-th 8k+1 prime plus n-th 8k+7 prime)/8.

Terms

a(0) =3a(1) =8a(2) =13a(3) =17a(4) =21a(5) =24a(6) =30a(7) =40a(8) =48a(9) =51a(10) =56a(11) =60a(12) =67a(13) =72a(14) =77a(15) =84a(16) =90a(17) =99a(18) =102a(19) =105a(20) =119a(21) =126a(22) =130a(23) =134a(24) =136a(25) =140a(26) =155a(27) =160a(28) =174a(29) =177