login
a(0)=1, a(1)=8, a(n) = sum_{k=0}^{k=n-1} 8^k a(k).
0

%I #8 Sep 08 2022 08:44:40

%S 1,8,65,4225,2167425,8879940225,290986761233025,76280724523431338625,

%T 159972350276487602091434625,2683890834588642498097652544938625,

%U 360225732702402245287553744812732691882625

%N a(0)=1, a(1)=8, a(n) = sum_{k=0}^{k=n-1} 8^k a(k).

%F a(n) = (8^(n-2) + 1) * a(n-1). - _Vincenzo Librandi_, Nov 11 2012

%o (Magma) I:=[1, 8, 65]; [n le 3 select I[n] else (8^(n-2)+1)*Self(n-1): n in [1..15]]; // _Vincenzo Librandi_, Nov 11 2012

%K nonn,easy

%O 0,2

%A _Olivier GĂ©rard_