a(n) is the least common multiple of the nonzero digits in factorial base expansion of 1/n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =1a(6) =6a(7) =3a(8) =6a(9) =2a(10) =60a(11) =2a(12) =120a(13) =3a(14) =3a(15) =6a(16) =1008a(17) =4a(18) =51480a(19) =1a(20) =4a(21) =30a(22) =6930a(23) =1a(24) =140a(25) =36a(26) =60a(27) =20a(28) =16380a(29) =4