a(n) = (prime(n)+1)*(prime(n+1)+1)/4.

Terms

a(0) =3a(1) =6a(2) =12a(3) =24a(4) =42a(5) =63a(6) =90a(7) =120a(8) =180a(9) =240a(10) =304a(11) =399a(12) =462a(13) =528a(14) =648a(15) =810a(16) =930a(17) =1054a(18) =1224a(19) =1332a(20) =1480a(21) =1680a(22) =1890a(23) =2205a(24) =2499a(25) =2652a(26) =2808a(27) =2970a(28) =3135a(29) =3648