Sum_{k=1..2*n-1} J(n,k)*k where J(i,j) is the Jacobi symbol.

Terms

a(0) =1a(1) =-2a(2) =-2a(3) =16a(4) =0a(5) =-12a(6) =6a(7) =0a(8) =108a(9) =-28a(10) =-46a(11) =0a(12) =0a(13) =-40a(14) =20a(15) =256a(16) =0a(17) =-8a(18) =-118a(19) =0a(20) =0a(21) =-92a(22) =50a(23) =0a(24) =1000a(25) =-100a(26) =14a(27) =0a(28) =0a(29) =-136