This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A155660 #19 Aug 03 2024 17:03:29
%S A155660 1,3,33,387,4161,42243,413793,3959427,37281921,347066883,3204309153,
%T A155660 29403732867,268588249281,2444976817923,22198569382113,
%U A155660 201143570584707,1819787258282241,16444551185679363,148466221699088673,1339452822487618947,12077873192759316801,108860443267429075203
%N A155660 a(n) = 9^n - 7^n + 1.
%H A155660 Paolo Xausa, <a href="/A155660/b155660.txt">Table of n, a(n) for n = 0..1000</a>
%H A155660 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (17,-79,63).
%F A155660 G.f.: 1/(1-9*x)-1/(1-7*x)+1/(1-x).
%F A155660 E.g.f.: exp(9*x)-exp(7*x)+exp(x).
%F A155660 a(n) = 16*a(n-1)-63*a(n-2)+48 with a(0) = 1, a(1) = 3. - _Vincenzo Librandi_, Jul 21 2010
%t A155660 LinearRecurrence[{17,-79,63},{1,3,33},30] (* _Harvey P. Dale_, Feb 25 2015 *)
%o A155660 (PARI) a(n)=9^n-7^n+1 \\ _Charles R Greathouse IV_, Jun 11 2015
%Y A155660 Cf. A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645, A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657, A155658, A155659.
%K A155660 nonn,easy
%O A155660 0,2
%A A155660 _Mohammad K. Azarian_, Jan 31 2009