Exactly half of first a(n) terms of Kolakoski sequence A000002 are 1's (not known to be infinite).

Terms

a(0) =0a(1) =2a(2) =4a(3) =6a(4) =8a(5) =10a(6) =14a(7) =16a(8) =18a(9) =20a(10) =22a(11) =24a(12) =26a(13) =28a(14) =30a(15) =36a(16) =38a(17) =40a(18) =42a(19) =44a(20) =46a(21) =48a(22) =50a(23) =54a(24) =56a(25) =58a(26) =60a(27) =62a(28) =64a(29) =68