Number of binary "privileged words" of length n.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =4a(5) =8a(6) =8a(7) =16a(8) =20a(9) =40a(10) =60a(11) =108a(12) =176a(13) =328a(14) =568a(15) =1040a(16) =1848a(17) =3388a(18) =6132a(19) =11332a(20) =20788a(21) =38576a(22) =71444a(23) =133256a(24) =248676a(25) =466264a(26) =875408a(27) =1649236a(28) =3112220a(29) =5888548