a(n) is the least k > 0 such that 1+k, 1+2*k, ..., 1+n*k are pairwise coprime.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =6a(6) =6a(7) =30a(8) =30a(9) =60a(10) =60a(11) =210a(12) =210a(13) =210a(14) =210a(15) =210a(16) =210a(17) =210a(18) =2310a(19) =2310a(20) =2310a(21) =2310a(22) =18480a(23) =120120a(24) =120120a(25) =150150a(26) =150150a(27) =150150a(28) =150150a(29) =660660