Inverse of number triangle A127967.

Terms

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