Number of Lyndon words on {1,2,3} with an odd number of 1's and an odd number of 2's.

Terms

a(0) =0a(1) =1a(2) =2a(3) =5a(4) =12a(5) =30a(6) =78a(7) =205a(8) =546a(9) =1476a(10) =4026a(11) =11070a(12) =30660a(13) =85410a(14) =239144a(15) =672605a(16) =1899120a(17) =5380830a(18) =15292914a(19) =43584804a(20) =124527988a(21) =356602950a(22) =1023295422a(23) =2941974270a(24) =8472886092a(25) =24441017580a(26) =70607383938