T(2n+5,n), array T as in A051168; a count of Lyndon words.

Terms

a(0) =0a(1) =1a(2) =4a(3) =15a(4) =55a(5) =200a(6) =728a(7) =2652a(8) =9690a(9) =35530a(10) =130750a(11) =482885a(12) =1789515a(13) =6653325a(14) =24812400a(15) =92798375a(16) =347993910a(17) =1308233790a(18) =4929576600a(19) =18615637950a(20) =70441574000a(21) =267058714626