a(n) = Sum_{k=1..8} n^k.

Terms

a(0) =0a(1) =8a(2) =510a(3) =9840a(4) =87380a(5) =488280a(6) =2015538a(7) =6725600a(8) =19173960a(9) =48427560a(10) =111111110a(11) =235794768a(12) =469070940a(13) =883708280a(14) =1589311290a(15) =2745954240a(16) =4581298448a(17) =7411742280a(18) =11668193550a(19) =17927094320a(20) =26947368420a(21) =39714002328a(22) =57489010370a(23) =81870575520a(24) =114861197400