Number of cubefree words of length n on two letters.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =16a(6) =24a(7) =36a(8) =56a(9) =80a(10) =118a(11) =174a(12) =254a(13) =378a(14) =554a(15) =802a(16) =1168a(17) =1716a(18) =2502a(19) =3650a(20) =5324a(21) =7754a(22) =11320a(23) =16502a(24) =24054a(25) =35058a(26) =51144a(27) =74540a(28) =108664a(29) =158372