a(n) = (1/1 - 1/2 + ... + (-1)^(n-1)/n)*lcm{1..n}.

Terms

a(0) =1a(1) =1a(2) =5a(3) =7a(4) =47a(5) =37a(6) =319a(7) =533a(8) =1879a(9) =1627a(10) =20417a(11) =18107a(12) =263111a(13) =237371a(14) =261395a(15) =477745a(16) =8842385a(17) =8161705a(18) =167324635a(19) =155685007a(20) =166770367a(21) =156188887a(22) =3825136961a(23) =3602044091a(24) =19081066231a(25) =18051406831a(26) =57128792093a(27) =54260455193