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 A140788 #17 Apr 02 2025 20:28:56
%S A140788 8,26,98,386,1538,6146,24578,98306,393218,1572866,6291458,25165826,
%T A140788 100663298,402653186,1610612738,6442450946,25769803778,103079215106,
%U A140788 412316860418,1649267441666,6597069766658,26388279066626,105553116266498,422212465065986,1688849860263938
%N A140788 a(n) = 6*4^n + 2.
%H A140788 Vincenzo Librandi, <a href="/A140788/b140788.txt">Table of n, a(n) for n = 0..1000</a>
%H A140788 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,-4).
%F A140788 a(n) = 2*A140660(n).
%F A140788 From _R. J. Mathar_, Feb 07 2009: (Start)
%F A140788 a(n) = 5*a(n-1) - 4*a(n-2).
%F A140788 G.f.: 2*(4-7*x)/((1-x)*(1-4*x)). (End)
%F A140788 E.g.f.: 2*exp(x)*(3*exp(3*x) + 1). - _Elmo R. Oliveira_, Apr 02 2025
%t A140788 6*4^Range[0,30]+2 (* or *) LinearRecurrence[{5,-4},{8,26},30] (* _Harvey P. Dale_, Apr 15 2019 *)
%o A140788 (Magma) [6*4^n+2: n in [0..30]]; // _Vincenzo Librandi_, Aug 08 2011
%Y A140788 Cf. A140660.
%K A140788 nonn,easy
%O A140788 0,1
%A A140788 _Paul Curtz_, Jul 14 2008
%E A140788 More terms from _R. J. Mathar_, Feb 07 2009