Consider the Watanabe tag system defined in A291067; a(n) = number of binary words of length n which terminate at the empty word.

A291780

Consider the Watanabe tag system defined in A291067; a(n) = number of binary words of length n which terminate at the empty word.

Terms

    a(0) =2a(1) =4a(2) =4a(3) =4a(4) =16a(5) =32a(6) =64a(7) =128a(8) =128a(9) =320a(10) =1152a(11) =1792a(12) =3584a(13) =8704a(14) =16384a(15) =28672a(16) =65536a(17) =118784a(18) =221184a(19) =483328a(20) =851968a(21) =1720320a(22) =3866624a(23) =6815744a(24) =14483456a(25) =31719424a(26) =55574528a(27) =113770496a(28) =246939648a(29) =438304768

External references