a(n) = n^7 - n^6.

Terms

a(0) =0a(1) =0a(2) =64a(3) =1458a(4) =12288a(5) =62500a(6) =233280a(7) =705894a(8) =1835008a(9) =4251528a(10) =9000000a(11) =17715610a(12) =32845824a(13) =57921708a(14) =97883968a(15) =159468750a(16) =251658240a(17) =386201104a(18) =578207808a(19) =846825858a(20) =1216000000a(21) =1715322420a(22) =2380977984a(23) =3256789558a(24) =4395368448a(25) =5859375000a(26) =7722894400a(27) =10072932714