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 A155663 #19 Aug 03 2024 16:49:12
%S A155663 1,16,144,1240,10656,91816,793584,6880120,59823936,521638216,
%T A155663 4560526224,39970994200,351149013216,3091621642216,27274838966064,
%U A155663 241075504183480,2134495165562496,18928981513351816,168109033806481104,1494966905748847960,13310586963663775776
%N A155663 a(n) = 9^n + 8^n - 1.
%H A155663 Paolo Xausa, <a href="/A155663/b155663.txt">Table of n, a(n) for n = 0..1000</a>
%H A155663 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (18,-89,72).
%F A155663 G.f.: 1/(1-9*x)+1/(1-8*x)-1/(1-x).
%F A155663 E.g.f.: exp(9*x)+exp(8*x)-exp(x).
%F A155663 a(n) = 17*a(n-1)-72*a(n-2)-56 with a(0) = 1, a(1) = 16. - _Vincenzo Librandi_, Jul 21 2010
%t A155663 Table[9^n+8^n-1,{n,0,20}] (* or *) LinearRecurrence[{18,-89,72},{1,16,144},20] (* _Harvey P. Dale_, Jun 14 2016 *)
%o A155663 (PARI) a(n)=9^n+8^n-1 \\ _Charles R Greathouse IV_, Jun 11 2015
%Y A155663 Cf. A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657, A155658, A155659, A155660, A155661, A155662.
%K A155663 nonn,easy
%O A155663 0,2
%A A155663 _Mohammad K. Azarian_, Jan 31 2009