Number of binary strings of length n having a cyclic shift that is a palindrome.

Terms

a(0) =1a(1) =2a(2) =2a(3) =8a(4) =6a(5) =32a(6) =20a(7) =100a(8) =54a(9) =260a(10) =152a(11) =684a(12) =348a(13) =1640a(14) =884a(15) =3728a(16) =1974a(17) =8672a(18) =4556a(19) =19420a(20) =10056a(21) =42736a(22) =22508a(23) =94164a(24) =48636a(25) =204632a(26) =106472a(27) =441764a(28) =228444a(29) =950216