%I #17 Mar 10 2022 05:31:17

%S 1,11,103,1007,10015,100031,1000063,10000127,100000255,1000000511,

%T 10000001023,100000002047,1000000004095,10000000008191,

%U 100000000016383,1000000000032767,10000000000065535,100000000000131071

%N 10^n+2^n-1.

%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (13,-32,20).

%F G.f.: 1/(1-10*x)+1/(1-2*x)-1/(1-x). E.g.f.: e^(10*x)+e^(2*x)-e^x.

%F a(n)=12*a(n-1)-20*a(n-2)-9 with a(0)=1, a(1)=11 - _Vincenzo Librandi_, Jul 21 2010

%F a(0)=1, a(1)=11, a(2)=103, a(n)=13*a(n-1)-32*a(n-2)+20*a(n-3). - _Harvey P. Dale_, Mar 07 2015

%F a(n) = A050621(n+1)-1. - _R. J. Mathar_, Mar 10 2022

%t LinearRecurrence[{13,-32,20},{1,11,103},20] (* _Harvey P. Dale_, Mar 07 2015 *)

%o (PARI) a(n)=10^n+2^n-1^n \\ _Charles R Greathouse IV_, Jun 11 2015

%Y Cf. A074501, A074600, A005057, A005056, A099393, A155588, A155590, A155592, A155593.

%K nonn,easy

%O 0,2

%A _Mohammad K. Azarian_, Jan 24 2009