Number of nonnegative integers with property that their base 10/7 expansion has n digits.

Terms

a(0) =10a(1) =10a(2) =10a(3) =20a(4) =30a(5) =40a(6) =60a(7) =80a(8) =120a(9) =170a(10) =240a(11) =340a(12) =490a(13) =700a(14) =1000a(15) =1430a(16) =2040a(17) =2910a(18) =4160a(19) =5940a(20) =8490a(21) =12130a(22) =17330a(23) =24750a(24) =35360a(25) =50520a(26) =72170a(27) =103100a(28) =147280a(29) =210400