a(2n) = A164555(n). a(2n+1) = A027641(n).

Terms

a(0) =1a(1) =1a(2) =1a(3) =-1a(4) =1a(5) =1a(6) =0a(7) =0a(8) =-1a(9) =-1a(10) =0a(11) =0a(12) =1a(13) =1a(14) =0a(15) =0a(16) =-1a(17) =-1a(18) =0a(19) =0a(20) =5a(21) =5a(22) =0a(23) =0a(24) =-691a(25) =-691a(26) =0a(27) =0a(28) =7a(29) =7