a(n) = lcm_{k=1..n} (prime(k) + 1).

Terms

a(0) =3a(1) =12a(2) =12a(3) =24a(4) =24a(5) =168a(6) =504a(7) =2520a(8) =2520a(9) =2520a(10) =10080a(11) =191520a(12) =191520a(13) =2106720a(14) =2106720a(15) =6320160a(16) =6320160a(17) =195924960a(18) =3330724320a(19) =3330724320a(20) =123236799840a(21) =123236799840a(22) =123236799840a(23) =123236799840a(24) =862657598880a(25) =862657598880