Bisection of A008705.

Terms

a(0) =-1a(1) =5a(2) =-6a(3) =41a(4) =-85a(5) =-2069a(6) =8605a(7) =3990a(8) =36685a(9) =-254525a(10) =-3603805a(11) =13479425a(12) =23579969a(13) =237487433a(14) =-1795846200a(15) =-6788705842a(16) =44427298525a(17) =-48251561329