Map n = Sum c_i 10^i to a(n) = Sum c_i 7^i.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =7a(8) =8a(9) =9a(10) =7a(11) =8a(12) =9a(13) =10a(14) =11a(15) =12a(16) =13a(17) =14a(18) =15a(19) =16a(20) =14a(21) =15a(22) =16a(23) =17a(24) =18a(25) =19a(26) =20a(27) =21a(28) =22a(29) =23