Number of length-n ternary words having at most 5 palindromic subwords (including the empty word).

Terms

a(0) =1a(1) =3a(2) =9a(3) =27a(4) =81a(5) =42a(6) =54a(7) =66a(8) =78a(9) =96a(10) =120a(11) =144a(12) =174a(13) =216a(14) =264a(15) =318a(16) =390a(17) =480a(18) =582a(19) =708a(20) =870a(21) =1062a(22) =1290a(23) =1578a(24) =1932a(25) =2352a(26) =2868a(27) =3510a(28) =4284a(29) =5220