Numbers whose base-10 representation has the same nonzero number of 1's and 6's.

Terms

a(0) =16a(1) =61a(2) =106a(3) =126a(4) =136a(5) =146a(6) =156a(7) =160a(8) =162a(9) =163a(10) =164a(11) =165a(12) =167a(13) =168a(14) =169a(15) =176a(16) =186a(17) =196a(18) =216a(19) =261a(20) =316a(21) =361a(22) =416a(23) =461a(24) =516a(25) =561a(26) =601a(27) =610a(28) =612a(29) =613