Numbers whose base-10 representation has the same nonzero number of 0's and 5's.

Terms

a(0) =50a(1) =105a(2) =150a(3) =205a(4) =250a(5) =305a(6) =350a(7) =405a(8) =450a(9) =501a(10) =502a(11) =503a(12) =504a(13) =506a(14) =507a(15) =508a(16) =509a(17) =510a(18) =520a(19) =530a(20) =540a(21) =560a(22) =570a(23) =580a(24) =590a(25) =605a(26) =650a(27) =705a(28) =750a(29) =805