a(n) = n^6 - n.

Terms

a(0) =0a(1) =0a(2) =62a(3) =726a(4) =4092a(5) =15620a(6) =46650a(7) =117642a(8) =262136a(9) =531432a(10) =999990a(11) =1771550a(12) =2985972a(13) =4826796a(14) =7529522a(15) =11390610a(16) =16777200a(17) =24137552a(18) =34012206a(19) =47045862a(20) =63999980a(21) =85766100a(22) =113379882a(23) =148035866a(24) =191102952a(25) =244140600a(26) =308915750