Smallest multiple of n with digit sum = 3, or 0 if no such number exists, e.g. a(9k)= 0 = a(11k).

Terms

a(0) =3a(1) =12a(2) =3a(3) =12a(4) =30a(5) =12a(6) =21a(7) =120a(8) =0a(9) =30a(10) =0a(11) =12a(12) =10101a(13) =210a(14) =30a(15) =1200a(16) =102a(17) =0a(18) =11001a(19) =120a(20) =21a(21) =0a(22) =2001a(23) =120a(24) =300a(25) =101010a(26) =0a(27) =2100a(28) =2001a(29) =30