Number of palindromic binary strings of length n having no 4-runs of 1's.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =3a(5) =7a(6) =6a(7) =14a(8) =12a(9) =27a(10) =23a(11) =52a(12) =44a(13) =100a(14) =85a(15) =193a(16) =164a(17) =372a(18) =316a(19) =717a(20) =609a(21) =1382a(22) =1174a(23) =2664a(24) =2263a(25) =5135a(26) =4362a(27) =9898a(28) =8408a(29) =19079