a(n) = b(n+1)-2b(n) where b() is A134812.

Terms

a(0) =1a(1) =-3a(2) =3a(3) =0a(4) =-6a(5) =12a(6) =-12a(7) =0a(8) =24a(9) =-48a(10) =48a(11) =0a(12) =-96a(13) =192a(14) =-192a(15) =0a(16) =384a(17) =-768a(18) =768a(19) =0a(20) =-1536a(21) =3072a(22) =-3072a(23) =0a(24) =6144a(25) =-12288a(26) =12288a(27) =0a(28) =-24576a(29) =49152