n-th derivative of arctan(x) at x = 1, n >= 4.

Terms

a(0) =0a(1) =-3a(2) =15a(3) =-45a(4) =0a(5) =1260a(6) =-11340a(7) =56700a(8) =0a(9) =-3742200a(10) =48648600a(11) =-340540200a(12) =0a(13) =40864824000a(14) =-694702008000a(16) =0a(20) =0a(24) =0