If n is odd a(n) = 1, if n is even a(n) = 2^(n-1).

Terms

a(0) =1a(1) =2a(2) =1a(3) =8a(4) =1a(5) =32a(6) =1a(7) =128a(8) =1a(9) =512a(10) =1a(11) =2048a(12) =1a(13) =8192a(14) =1a(15) =32768a(16) =1a(17) =131072a(18) =1a(19) =524288a(20) =1a(21) =2097152a(22) =1a(23) =8388608a(24) =1a(25) =33554432a(26) =1a(27) =134217728a(28) =1a(29) =536870912