a(n) = Sum_{k=1..9} n^k.

Terms

a(0) =0a(1) =9a(2) =1022a(3) =29523a(4) =349524a(5) =2441405a(6) =12093234a(7) =47079207a(8) =153391688a(9) =435848049a(10) =1111111110a(11) =2593742459a(12) =5628851292a(13) =11488207653a(14) =22250358074a(15) =41189313615a(16) =73300775184a(17) =125999618777a(18) =210027483918a(19) =340614792099a(20) =538947368420a(21) =833994048909