a(n) = 1^n + 2^n + ... + 8^n.

Terms

a(0) =8a(1) =36a(2) =204a(3) =1296a(4) =8772a(5) =61776a(6) =446964a(7) =3297456a(8) =24684612a(9) =186884496a(10) =1427557524a(11) =10983260016a(12) =84998999652a(13) =660994932816