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 A155656 #18 Jul 28 2024 16:53:08
%S A155656 1,15,129,1071,8961,75855,649089,5606511,48811521,427774095,
%T A155656 3769259649,33358386351,296270823681,2638754838735,23555015527809,
%U A155656 210638693604591,1886253119421441,16909812213653775,151723048894909569,1362250612858365231,12237457725354540801
%N A155656 a(n) = 9^n + 7^n - 1.
%H A155656 Paolo Xausa, <a href="/A155656/b155656.txt">Table of n, a(n) for n = 0..1000</a>
%H A155656 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (17,-79,63).
%F A155656 G.f.: 1/(1-9*x) + 1/(1-7*x) - 1/(1-x).
%F A155656 E.g.f.: e^(9*x) + e^(7*x) - e^x.
%F A155656 a(n) = 16*a(n-1)-63*a(n-2)-48 with a(0) = 1, a(1) = 15. - _Vincenzo Librandi_, Jul 21 2010
%t A155656 Table[9^n + 7^n - 1, {n, 0, 25}] (* _Paolo Xausa_, Jul 28 2024 *)
%o A155656 (PARI) a(n)=9^n+7^n-1 \\ _Charles R Greathouse IV_, Jun 11 2015
%Y A155656 Cf. A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645, A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655.
%K A155656 nonn,easy
%O A155656 0,2
%A A155656 _Mohammad K. Azarian_, Jan 31 2009