a(n) = LCM of the integers b(k), over all k where 1 <= k <= n, where b(k) = the k-th integer from among those positive integers which are coprime to (n+1-k).

A132421

a(n) = LCM of the integers b(k), over all k where 1 <= k <= n, where b(k) = the k-th integer from among those positive integers which are coprime to (n+1-k).

Terms

    a(0) =1a(1) =2a(2) =3a(3) =20a(4) =420a(5) =90a(6) =1155a(7) =6552a(8) =990a(9) =340340a(10) =38798760a(11) =406980a(12) =314954640a(13) =30630600a(14) =489304530a(15) =18357939600a(16) =21649708080a(18) =181957885200a(20) =237972194460a(23) =892567605600

External references