a(n) = n^5 - n^4.

Terms

a(0) =0a(1) =0a(2) =16a(3) =162a(4) =768a(5) =2500a(6) =6480a(7) =14406a(8) =28672a(9) =52488a(10) =90000a(11) =146410a(12) =228096a(13) =342732a(14) =499408a(15) =708750a(16) =983040a(17) =1336336a(18) =1784592a(19) =2345778a(20) =3040000a(21) =3889620a(22) =4919376a(23) =6156502a(24) =7630848a(25) =9375000a(26) =11424400a(27) =13817466a(28) =16595712a(29) =19803868