(prime(n-1) + 1)*(prime(n+1) - 1).

Terms

a(0) =12a(1) =24a(2) =60a(3) =96a(4) =192a(5) =252a(6) =396a(7) =560a(8) =720a(9) =1080a(10) =1280a(11) =1596a(12) =1932a(13) =2288a(14) =2784a(15) =3240a(16) =3960a(17) =4340a(18) =4896a(19) =5616a(20) =6068a(21) =7040a(22) =8064a(23) =9000a(24) =9996a(25) =10812a(26) =11232a(27) =12096a(28) =13860a(29) =14820