a(n) = 4*prime(n)^2.

Terms

a(0) =16a(1) =36a(2) =100a(3) =196a(4) =484a(5) =676a(6) =1156a(7) =1444a(8) =2116a(9) =3364a(10) =3844a(11) =5476a(12) =6724a(13) =7396a(14) =8836a(15) =11236a(16) =13924a(17) =14884a(18) =17956a(19) =20164a(20) =21316a(21) =24964a(22) =27556a(23) =31684a(24) =37636a(25) =40804a(26) =42436a(27) =45796a(28) =47524a(29) =51076