Numbers with mirror symmetry about middle.

Terms

a(0) =0a(1) =1a(2) =8a(3) =11a(4) =88a(5) =101a(6) =111a(7) =181a(8) =808a(9) =818a(10) =888a(11) =1001a(12) =1111a(13) =1881a(14) =8008a(15) =8118a(16) =8888a(17) =10001a(18) =10101a(19) =10801a(20) =11011a(21) =11111a(22) =11811a(23) =18081a(24) =18181a(25) =18881a(26) =80008a(27) =80108a(28) =80808a(29) =81018