a(n) = n^6*(n^3 + 1)/2.

Terms

a(0) =0a(1) =1a(2) =288a(3) =10206a(4) =133120a(5) =984375a(6) =5062176a(7) =20235628a(8) =67239936a(9) =193975965a(10) =500500000a(11) =1179859626a(12) =2581383168a(13) =5304663091a(14) =10334288160a(15) =19227375000a(16) =34368126976a(17) =59306007033a(18) =99196651296a(19) =161367371830a(20) =256032000000a(21) =397182906351a(22) =603691298848a(23) =900650348676