Sum_{k=1..2*n-1} J(4*n,k)*k, where J(i,j) is the Jacobi symbol.

Terms

a(0) =1a(1) =-2a(2) =-4a(3) =16a(4) =0a(5) =-12a(6) =-16a(7) =0a(8) =54a(9) =-28a(10) =-28a(11) =0a(12) =0a(13) =-40a(14) =-48a(15) =256a(16) =0a(17) =-8a(18) =-76a(19) =0a(20) =0a(21) =-92a(22) =-80a(23) =0a(24) =500a(25) =-100a(26) =-4a(27) =0a(28) =0a(29) =-136