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 A064754 #26 May 05 2025 16:21:37
%S A064754 7,127,1535,16383,163839,1572863,14680063,134217727,1207959551,
%T A064754 10737418239,94489280511,824633720831,7146825580543,61572651155455,
%U A064754 527765581332479,4503599627370495,38280596832649215,324259173170675711,2738188573441261567,23058430092136939519
%N A064754 a(n) = n*8^n - 1.
%H A064754 Vincenzo Librandi, <a href="/A064754/b064754.txt">Table of n, a(n) for n = 1..1000</a>
%H A064754 Paul Leyland, <a href="http://www.leyland.vispa.com/numth/factorization/cullen_woodall/cw.htm">Factors of Cullen and Woodall numbers</a>.
%H A064754 Paul Leyland, <a href="http://www.leyland.vispa.com/numth/factorization/cullen_woodall/gcw.htm">Generalized Cullen and Woodall numbers</a>.
%H A064754 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (17,-80,64).
%F A064754 G.f.: x*(64*x^2 - 8*x - 7)/((x-1)*(8*x-1)^2). - _Colin Barker_, Oct 15 2012
%F A064754 a(n) = 17*a(n-1) - 80*a(n-2) + 64*a(n-3); a(1)=7, a(2)=127, a(3)=1535. - _Harvey P. Dale_, May 20 2013
%F A064754 From _Elmo R. Oliveira_, May 05 2025: (Start)
%F A064754 E.g.f.: 1 + exp(x)*(8*x*exp(7*x) - 1).
%F A064754 a(n) = A036294(n) - 1. (End)
%t A064754 Table[n*8^n-1,{n,20}] (* or *) LinearRecurrence[{17,-80,64},{7,127,1535},20] (* _Harvey P. Dale_, May 20 2013 *)
%o A064754 (Magma) [ n*8^n-1: n in [1..20]]; // _Vincenzo Librandi_, Sep 16 2011
%Y A064754 Cf. A003261, A036294.
%K A064754 nonn,easy
%O A064754 1,1
%A A064754 _N. J. A. Sloane_, Oct 19 2001