n-th 4k+1 prime plus n-th 4k+3 prime.

Terms

a(0) =8a(1) =20a(2) =28a(3) =48a(4) =60a(5) =72a(6) =96a(7) =108a(8) =132a(9) =156a(10) =168a(11) =180a(12) =192a(13) =216a(14) =244a(15) =276a(16) =288a(17) =312a(18) =332a(19) =356a(20) =364a(21) =408a(22) =424a(23) =440a(24) =468a(25) =492a(26) =504a(27) =520a(28) =544a(29) =576