a(n) = Sum_{k=0..n} (-2)^k * binomial(n,k)^3.

Terms

a(0) =1a(1) =-1a(2) =-11a(3) =47a(4) =241a(5) =-2281a(6) =-3779a(7) =104831a(8) =-110207a(9) =-4415281a(10) =16955269a(11) =161498831a(12) =-1252782959a(13) =-4376471737a(14) =73606867309a(15) =11876256767