a(n) = number of 1's between n-th 3 and (n+1)st 3 in A026600.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =2a(5) =0a(6) =2a(7) =0a(8) =1a(9) =1a(10) =2a(11) =0a(12) =2a(13) =0a(14) =2a(15) =0a(16) =1a(17) =1a(18) =2a(19) =0a(20) =2a(21) =0a(22) =1a(23) =1a(24) =1a(25) =2a(26) =0a(27) =1a(28) =2a(29) =0