Numbers n which divide the periodic part (with zeros at end) of the decimal expansion of 1/n.

Terms

a(0) =3a(1) =6a(2) =487a(3) =974a(4) =1461a(5) =2435a(6) =2922a(7) =4383a(8) =4870a(9) =7305a(10) =8766a(11) =12175a(12) =13149a(13) =14610a(14) =17532a(15) =21915a(16) =24350a(17) =26298a(18) =29220a(19) =36525a(20) =43830a(21) =48700a(22) =52596a(23) =65745a(24) =73050a(25) =87660a(26) =109575a(27) =131490a(28) =146100a(29) =219150