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 A164559 #16 Apr 18 2024 09:32:27 %S A164559 1,11,71,431,2591,15551,93311,559871,3359231,20155391,120932351, %T A164559 725594111,4353564671,26121388031,156728328191,940369969151, %U A164559 5642219814911,33853318889471,203119913336831,1218719480020991,7312316880125951,43873901280755711,263243407684534271 %N A164559 a(n) = 6^n/3 - 1. %H A164559 Vincenzo Librandi, <a href="/A164559/b164559.txt">Table of n, a(n) for n = 1..600</a> %H A164559 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (7,-6). %F A164559 a(n) = 6*a(n-1)+5 for n > 2; a(1) = 1, a(2) = 11. %F A164559 G.f.: x*(1+4*x)/((1-x)*(1-6*x)). %o A164559 (Magma) [ 6^n/3-1: n in [1..20] ]; %Y A164559 Cf. A000400 (powers of 6), A024062 (6^n-1), A164560. %K A164559 nonn,easy %O A164559 1,2 %A A164559 _Klaus Brockhaus_, Aug 16 2009