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 A174677 #33 Jul 30 2024 03:11:37
%S A174677 1,1,2,4,16,128,4096,1048576,8589934592,18014398509481984,
%T A174677 309485009821345068724781056,
%U A174677 11150372599265311570767859136324180752990208
%N A174677 a(n) = 2*a(n-1)*a(n-2) with a(0)=1 and a(1)=1.
%C A174677 a(n) is the number of node minimal AVL trees of height n. - _Alois P. Heinz_, Mar 13 2013
%H A174677 Vincenzo Librandi, <a href="/A174677/b174677.txt">Table of n, a(n) for n = 0..17</a>
%F A174677 a(n) = 2^(Fibonacci(n+1) - 1).
%F A174677 a(n) = 1/2 * A000301(n+1).
%t A174677 2^(Fibonacci[Range[15]] -1) (* _Vladimir Joseph Stephan Orlovsky_, Apr 19 2011 *)
%t A174677 Join[{1}, RecurrenceTable[{a[1]==1,a[2]==2,a[n]==2a[n-1]a[n-2]},a[n],{n, 12}]] (* _Harvey P. Dale_, Jul 07 2011 *)
%o A174677 (Magma) [2^(Fibonacci(n+1)-1): n in [0..10]]; // _Vincenzo Librandi_, Apr 24 2011
%o A174677 (SageMath) [2^(fibonacci(n+1) -1) for n in range(13)] # _G. C. Greubel_, Jul 30 2024
%Y A174677 Cf. A000045, A000301, A143897, A174666, A217298.
%K A174677 easy,nonn
%O A174677 0,3
%A A174677 _Giovanni Teofilatto_, Mar 26 2010
%E A174677 Formula index corrected by _R. J. Mathar_, Mar 30 2010
%E A174677 a(0)=1 prepended and name edited by _Alois P. Heinz_, Jul 05 2021