a(n)=A069521(n)/n.

Terms

a(0) =2a(1) =1a(2) =0a(3) =5a(4) =4a(5) =0a(6) =143a(7) =25a(8) =0a(9) =2a(10) =1a(11) =0a(12) =77a(13) =715a(14) =0a(15) =125a(16) =5882353a(17) =0a(18) =52631579a(19) =1a(20) =0a(21) =5a(22) =4347826087a(23) =0a(24) =8a(25) =385a(26) =0a(27) =3575a(29) =0a(30) =0