T(n,k) = Number of squarefree words of length n in a (k+1)-ary alphabet.

Terms

a(0) =2a(1) =3a(2) =2a(3) =4a(4) =6a(5) =2a(6) =5a(7) =12a(8) =12a(9) =0a(10) =6a(11) =20a(12) =36a(13) =18a(14) =0a(15) =7a(16) =30a(17) =80a(18) =96a(19) =30a(20) =0a(21) =8a(22) =42a(23) =150a(24) =300a(25) =264a(26) =42a(27) =0a(28) =9a(29) =56