a(n) = Sum_{1 <= i < j < k <= n} (k*j*i)^3.

Terms

a(0) =0a(1) =0a(2) =0a(3) =216a(4) =16280a(5) =335655a(6) =3587535a(7) =25421200a(8) =135459216a(9) =584760870a(10) =2145870870a(11) =6918983280a(12) =20073184560a(13) =53334782501a(14) =131555523645a(15) =304453955520a(16) =666698215360