A bisection of A222803.

Terms

a(0) =0a(1) =11a(2) =-13a(3) =29a(4) =109a(5) =-67a(6) =6571a(7) =-415a(8) =162573a(9) =-23663513a(10) =10230003a(11) =-564409a(12) =854671223a(13) =-3380281a(14) =66346781597a(17) =-513555084749