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a(n) = (16*10^n-7)/9.
2

%I #12 Sep 08 2022 08:46:09

%S 1,17,177,1777,17777,177777,1777777,17777777,177777777,1777777777,

%T 17777777777,177777777777,1777777777777,17777777777777,

%U 177777777777777,1777777777777777,17777777777777777,177777777777777777,1777777777777777777,17777777777777777777

%N a(n) = (16*10^n-7)/9.

%H Vincenzo Librandi, <a href="/A246058/b246058.txt">Table of n, a(n) for n = 0..100</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).

%F G.f.: (1+6*x)/((1-x)*(1-10*x)).

%F a(n) = 11*a(n-1) - 10*a(n-2).

%t Table[(16 10^n - 7)/9, {n, 0, 20}]

%o (Magma) [(16*10^n-7)/9: n in [0..20]]

%Y Cf. similar sequences listed in A246057.

%K nonn,easy

%O 0,2

%A _Vincenzo Librandi_, Aug 13 2014