A177074 - OEIS

%I #23 Sep 08 2022 08:45:53

%S 15,285,2985,29985,299985,2999985,29999985,299999985,2999999985,

%T 29999999985,299999999985,2999999999985,29999999999985,

%U 299999999999985,2999999999999985,29999999999999985,299999999999999985

%N 3*(10^n-5).

%C Apparently 15 times the entries in A067272. - _R. J. Mathar_, Aug 24 2011

%H Vincenzo Librandi, <a href="/A177074/b177074.txt">Table of n, a(n) for n = 1..100</a>

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

%F G.f. 15*x*(1+8*x) / ( (10*x-1)*(x-1) ). - _R. J. Mathar_, Aug 24 2011

%F a(n) = 11*a(n-1) - 10*a(n-2), n>1. - _Vincenzo Librandi_, Apr 26 2014

%t Table[3*(10^n-5),{n,20}] (* or *) LinearRecurrence[{11,-10},{15,285},20] (* _Harvey P. Dale_, Apr 25 2014 *)

%t CoefficientList[Series[15 (1 + 8 x)/((10 x - 1) (x - 1)), {x, 0, 40}], x] (* _Vincenzo Librandi_, Apr 26 2014 *)

%o (Magma) [3*(10^n-5): n in [1..20]]; // _Vincenzo Librandi_, Apr 26 2014

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_