a(n) is the least number m such that (m+n)!/m! = (m+1)*(m+2)*...*(m+n) divides lcm(1,...,m).

Terms

a(0) =5a(1) =13a(2) =19a(3) =32a(4) =73a(5) =89a(6) =140a(7) =199a(8) =294a(9) =468a(10) =1072a(11) =1072a(12) =1072a(13) =2161a(14) =2976a(15) =32805a(16) =32806a(17) =65732a(18) =65732a(19) =262153a(20) =262154a(21) =524457a(22) =524640a(23) =4194464a(24) =4194464a(25) =8388640a(26) =8388640a(27) =33554432a(28) =33554432a(29) =67108992