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 A023365 #57 Oct 16 2024 09:21:04
%S A023365 2,8,512,134217728,2417851639229258349412352,
%T A023365 14134776518227074636666380005943348126619871175004951664972849610340958208
%N A023365 a(n) = 2^(3^(n-1)).
%C A023365 a(n+1) = a(n) converted to base 8 from base 2 (written in base 10).
%C A023365 Number of disjunctive-normal forms of n-1 variables (either with x, or x-negated or without x). - _Labos Elemer_, Jul 24 2003
%C A023365 a(n)*Psi(3^n,x), with the (monic) minimal polynomial Psi(3^n,x) of cos(2*Pi/3^n), becomes an integer polynomial with coefficient 1 of x^0.
%C A023365 E.g., 8*Psi(9,x)=8*(x^3 - (3/4)*x + 1/8) = 8*x^3 - 6*x + 1.
%C A023365 See A181875/A181876, A181877 and the W. Lang link under A181875. - _Wolfdieter Lang_, Feb 24 2011
%C A023365 The next term (a(7)) has 220 digits. - _Harvey P. Dale_, Aug 10 2014
%C A023365 These seem to be the reduced denominators of Newton's iteration for 1/sqrt(2), starting with 1/2. - _Steven Finch_, Oct 08 2024
%H A023365 Vincenzo Librandi, <a href="/A023365/b023365.txt">Table of n, a(n) for n = 1..8</a>
%H A023365 W. van der Aalst, J. Buijs and B. van Dongen, <a href="http://wwwis.win.tue.nl/~wvdaalst/publications/p655.pdf">Towards Improving the Representational Bias of Process Mining</a>, 2012. - From _N. J. A. Sloane_, Feb 03 2013
%H A023365 X. Gourdon and P. Sebah, <a href="http://numbers.computation.free.fr/Constants/Sqrt2/sqrt2.html">Pythagoras' Constant</a>. - From _Steven Finch_, Oct 07 2024
%F A023365 a(n) = a(n-1)^3.
%F A023365 a(n) = A000079(A000244(n-1)).
%F A023365 a(n+1) is conjectured to be the reduced denominator of b(n) = b(n-1)*(3/2 - b(n-1)^2); b(0) = 1/2. - _Steven Finch_, Oct 08 2024
%F A023365 Limit_{n -> oo} A376867(n-1)/a(n) = 1/sqrt(2) = A010503. - _Steven Finch_, Oct 08 2024
%t A023365 NestList[#^3&,2,6] (* _Harvey P. Dale_, Aug 10 2014 *)
%o A023365 (Magma) [Floor(2^(3^(n-1))): n in [1..10]]; // _Vincenzo Librandi_, Aug 11 2014
%o A023365 (Python)
%o A023365 def A023365(n): return 1<<3**(n-1) # _Chai Wah Wu_, Oct 11 2024
%o A023365 (Sage) [2^(3^(n-1)) for n in range(1,8)] # _Stefano Spezia_, Oct 15 2024
%Y A023365 Cf. A000079, A000244, A010503, A181875, A181876, A181877, A376867.
%K A023365 nonn
%O A023365 1,1
%A A023365 _David W. Wilson_