Number of binary strings of length n that avoid the pattern x x^R x (x^R is the reversal of x).

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =16a(6) =24a(7) =34a(8) =50a(9) =72a(10) =100a(11) =138a(12) =188a(13) =254a(14) =342a(15) =454a(16) =598a(17) =784a(18) =1018a(19) =1316a(20) =1694a(21) =2166a(22) =2756a(23) =3492a(24) =4404a(25) =5530a(26) =6920a(27) =8626a(28) =10712a(29) =13264