Number of length-n ternary strings x with the property that if w is a subword of x and |w| >= 3, then w reversed is not a subword of x.

A330010

Number of length-n ternary strings x with the property that if w is a subword of x and |w| >= 3, then w reversed is not a subword of x.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =18a(4) =30a(5) =48a(6) =78a(7) =126a(8) =204a(9) =330a(10) =534a(11) =864a(12) =1398a(13) =2262a(14) =3660a(15) =5922a(16) =9582a(17) =15504a(18) =25086a(19) =40590a(20) =65676a(21) =106266a(22) =171942a(23) =278208a(24) =450150a(25) =728358a(26) =1178508a(27) =1906866a(28) =3085374a(29) =4992240

External references