Sequence shifts left four places under Weigh transform with a(n) = signum(n) for n<4.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =2a(8) =2a(9) =3a(10) =4a(11) =6a(12) =8a(13) =12a(14) =18a(15) =26a(16) =39a(17) =58a(18) =88a(19) =133a(20) =202a(21) =308a(22) =472a(23) =725a(24) =1116a(25) =1725a(26) =2669a(27) =4141a(28) =6437a(29) =10027