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A155593 a(n) = 9^n + 2^n - 1. 18

%I #20 Sep 09 2022 18:58:54

%S 1,10,84,736,6576,59080,531504,4783096,43046976,387421000,3486785424,

%T 31381061656,282429540576,2541865836520,22876792471344,

%U 205891132127416,1853020188917376,16677181699797640,150094635297261264

%N a(n) = 9^n + 2^n - 1.

%H Harvey P. Dale, <a href="/A155593/b155593.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (12,-29,18).

%F G.f.: 1/(1-9*x)+1/(1-2*x)-1/(1-x).

%F E.g.f.: e^(9*x)+e^(2*x)-e^x.

%F a(n) = 11*a(n-1)-18*a(n-2)-8 with a(0)=1, a(1)=10. - _Vincenzo Librandi_, Jul 21 2010

%F a(n) = A074604(n)-1. - _R. J. Mathar_, Mar 10 2022

%t Table[9^n+2^n-1,{n,0,30}] (* or *) LinearRecurrence[{12,-29,18},{1,10,84},30] (* _Harvey P. Dale_, Sep 09 2022 *)

%o (PARI) a(n)=9^n+2^n-1^n \\ _Charles R Greathouse IV_, Jun 11 2015

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

%K nonn,easy

%O 0,2

%A _Mohammad K. Azarian_, Jan 24 2009

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Last modified April 24 07:54 EDT 2024. Contains 371922 sequences. (Running on oeis4.)