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 A036544 #16 Mar 11 2025 13:45:50
%S A036544 2,4,8,32,256,2480,24704,246928,2469152,24691376,246913600,2469135824,
%T A036544 24691358048,246913580272,2469135802496,24691358024720,246913580246944
%N A036544 a(n) = (2*(1 + n + (((10^n-1)/9) - n)/9)).
%C A036544 Result of applying extrapolator to terms 3-7 of A000301.
%H A036544 Vincenzo Librandi, <a href="/A036544/b036544.txt">Table of n, a(n) for n = 0..1000</a>
%H A036544 A. Karttunen, <a href="http://www.iki.fi/%7ekarttu/software/extrapolator.cl">Lisp Source (see function g and sequence cddr_of_mult2last)</a>
%H A036544 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (12, -21, 10).
%F A036544 a(n) = (2/81)*(72*n + 10^n + 80).
%F A036544 G.f.: 2*(1 - 10*x + x^2)/((1-10*x)*(1-x)^2). - _Bruno Berselli_, Nov 11 2011
%t A036544 LinearRecurrence[{12,-21,10},{2,4,8},20] (* _Harvey P. Dale_, Mar 11 2025 *)
%o A036544 (Magma) [(2*(1+n+(((10^n-1)/9)-n)/9)): n in [0..30]]; // _Vincenzo Librandi_, Nov 11 2011
%K A036544 nonn,easy
%O A036544 0,1
%A A036544 Antti Karttunen