a(n) = n^6*(n + 1)/2.

Terms

a(0) =0a(1) =1a(2) =96a(3) =1458a(4) =10240a(5) =46875a(6) =163296a(7) =470596a(8) =1179648a(9) =2657205a(10) =5500000a(11) =10629366a(12) =19408896a(13) =33787663a(14) =56471520a(15) =91125000a(16) =142606336a(17) =217238121a(18) =323116128a(19) =470458810a(20) =672000000a(21) =943427331a(22) =1303868896a(23) =1776430668a(24) =2388787200a(25) =3173828125a(26) =4170362976