Signed version of A035607.

Terms

a(0) =1a(1) =-2a(2) =1a(3) =2a(4) =-4a(5) =1a(6) =-2a(7) =8a(8) =-6a(9) =1a(10) =2a(11) =-12a(12) =18a(13) =-8a(14) =1a(15) =-2a(16) =16a(17) =-38a(18) =32a(19) =-10a(20) =1a(21) =2a(22) =-20a(23) =66a(24) =-88a(25) =50a(26) =-12a(27) =1a(28) =-2a(29) =24