a(n) = 4*(2^(n^2-n+1)*(n^2-n)-n+3).A087487a(n) = 4*(2^(n^2-n+1)*(n^2-n)-n+3).Terms a(0) =8a(1) =68a(2) =3072a(3) =393212a(4) =167772152a(5) =257698037748External referencesoeis: A087487