Numbers in which parity of the decimal digits alternates.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =7a(8) =8a(9) =9a(10) =10a(11) =12a(12) =14a(13) =16a(14) =18a(15) =21a(16) =23a(17) =25a(18) =27a(19) =29a(20) =30a(21) =32a(22) =34a(23) =36a(24) =38a(25) =41a(26) =43a(27) =45a(28) =47a(29) =49