Transform of the finite sequence (1, 0, -1, 0, 1, 0, -1) by the T_{1,1} transform (see link).

Terms

a(0) =2a(1) =4a(2) =9a(3) =23a(4) =55a(5) =126a(6) =293a(7) =680a(8) =1581a(9) =3676a(10) =8546a(11) =19867a(12) =46185a(13) =107367a(14) =249598a(15) =580245a(16) =1348906a(17) =3135826a(18) =7289911a(19) =16946987a(20) =39396965a(21) =91586832a(22) =212913553a(23) =494963960a(24) =1150651606a(25) =2674940451a(26) =6218482101a(27) =14456217007a(28) =33606627270