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%I #27 Sep 08 2022 08:44:47
%S 2,8,512,134217728,2417851639229258349412352,
%T 14134776518227074636666380005943348126619871175004951664972849610340958208
%N a(n) = 2^(3^(n-1)).
%C a(n+1) = a(n) converted to base 8 from base 2 (written in base 10).
%C Number of disjunctive-normal forms of n-1 variables (either with x, or x-negated or without x). - _Labos Elemer_, Jul 24 2003
%C 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 E.g., 8*Psi(9,x)=8*(x^3 - (3/4)*x + 1/8) = 8*x^3 - 6*x + 1.
%C See A181875/A181876, A181877 and the W. Lang link under A181875. - _Wolfdieter Lang_, Feb 24 2011
%C The next term (a(7)) has 220 digits. - _Harvey P. Dale_, Aug 10 2014
%H Vincenzo Librandi, <a href="/A023365/b023365.txt">Table of n, a(n) for n = 1..8</a>
%H 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
%F a(n) = a(n-1)^3.
%t NestList[#^3&,2,6] (* _Harvey P. Dale_, Aug 10 2014 *)
%o (Magma) [Floor(2^(3^(n-1))): n in [1..10]]; // _Vincenzo Librandi_, Aug 11 2014
%Y a(n) = A000079(A000244(n-1)).
%K nonn
%O 1,1
%A _David W. Wilson_
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