a(n+6) = 6*a(n+4) - 12*a(n+2) + 8*a(n), a(0)..a(5) = 8,0,9,0,8,0.

Terms

a(0) =8a(1) =0a(2) =9a(3) =0a(4) =8a(5) =0a(6) =4a(7) =0a(8) =0a(9) =0a(10) =16a(11) =0a(12) =128a(13) =0a(14) =576a(15) =0a(16) =2048a(17) =0a(18) =6400a(19) =0a(20) =18432a(21) =0a(22) =50176a(23) =0a(24) =131072a(25) =0a(26) =331776a(27) =0a(28) =819200a(29) =0