Unbranched catafusenes, mirror-symmetrical.

Terms

a(0) =0a(1) =0a(2) =1a(3) =1a(4) =4a(5) =3a(6) =12a(7) =10a(8) =34a(9) =28a(10) =97a(11) =81a(12) =271a(13) =226a(14) =764a(15) =638a(16) =2141a(17) =1787a(18) =6025a(19) =5030a(20) =16924a(21) =14116a(22) =47623a(23) =39727a(24) =133934a(25) =111655a(26) =377003a(27) =314297a(28) =1061064a(29) =884199