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 A248604 #19 May 15 2023 12:15:25
%S A248604 1,3,5,9,13,21,37,69,133,261,517,1029,2053,4101,8197,16389,32773,
%T A248604 65541,131077,262149,524293,1048581,2097157,4194309,8388613,16777221,
%U A248604 33554437,67108869,134217733,268435461,536870917,1073741829,2147483653,4294967301,8589934597
%N A248604 Numbers a(n) which are the minimum number of moves needed in a variation of the tower of Hanoi with 4 towers and n disks.
%H A248604 Stefano Spezia, <a href="/A248604/b248604.txt">Table of n, a(n) for n = 1..3300</a>
%H A248604 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2).
%F A248604 a(1)=1; a(2)=3; a(3)=5; a(n) = 5 + 2^(n-2) for n > 3.
%F A248604 G.f.: x*(1 - 2*x^2 - 4*x^4)/((1 - x)*(1 - 2*x)). - _Stefano Spezia_, May 15 2023
%t A248604 LinearRecurrence[{3,-2},{1,3,5,9,13},40] (* _Harvey P. Dale_, May 10 2019 *)
%Y A248604 Cf. A168614.
%K A248604 nonn,easy
%O A248604 1,2
%A A248604 _Aaron C. Horak_, Oct 09 2014
%E A248604 More terms from _Harvey P. Dale_, May 10 2019