Numbers whose base-9 representation has the same nonzero number of 1's and 4's.

Terms

a(0) =13a(1) =37a(2) =85a(3) =103a(4) =112a(5) =117a(6) =119a(7) =120a(8) =122a(9) =123a(10) =124a(11) =125a(12) =130a(13) =139a(14) =148a(15) =157a(16) =175a(17) =199a(18) =256a(19) =280a(20) =325a(21) =333a(22) =335a(23) =336a(24) =338a(25) =339a(26) =340a(27) =341a(28) =343a(29) =352