T(n,k)=Number of length-n 0..k arrays with no repeated value equal to the previous repeated value.

Terms

a(0) =2a(1) =3a(2) =4a(3) =4a(4) =9a(5) =6a(6) =5a(7) =16a(8) =24a(9) =10a(10) =6a(11) =25a(12) =60a(13) =66a(14) =14a(15) =7a(16) =36a(17) =120a(18) =228a(19) =174a(20) =22a(21) =8a(22) =49a(23) =210a(24) =580a(25) =852a(26) =462a(27) =30a(28) =9a(29) =64