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%I #26 Mar 02 2018 02:17:46
%S 1,1,1,8,2,4,27,3,9,64,4,16,125,5,25,216,6,36,343,7,49,512,8,64,729,9,
%T 81,1000,10,100,1331,11,121,1728,12,144,2197,13,169,2744,14,196,3375,
%U 15,225,4096,16,256,4913,17,289,5832,18,324,6859,19,361,8000,20,400
%N n^3 followed by n followed by n^2.
%H Reinhard Zumkeller, <a href="/A109614/b109614.txt">Table of n, a(n) for n = 1..3000</a>
%H <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,4,0,0,-6,0,0,4,0,0,-1).
%F From _R. J. Mathar_, Jun 26 2009: (Start)
%F a(n) = 4*a(n-3) - 6*a(n-6) + 4*a(n-9) - a(n-12).
%F G.f.: -(-1-x-x^2-4*x^3+2*x^4-x^6-x^7+x^8)/((x-1)^4*(1+x+x^2)^4). (End)
%F a(n) = floor((n+2)/3)^((-3*(n mod 3)^2 + 5*(n mod 3) + 4)/2). - _Luce ETIENNE_, Mar 01 2018
%t Table[{n^3,n,n^2},{n,20}]//Flatten (* or *) LinearRecurrence[{0,0,4,0,0,-6,0,0,4,0,0,-1},{1,1,1,8,2,4,27,3,9,64,4,16},60] (* _Harvey P. Dale_, Feb 25 2016 *)
%o (Haskell)
%o import Data.List (transpose)
%o a109614 n = a109614_list !! (n-1)
%o a109614_list = concat $ transpose
%o [tail a000578_list, a000027_list, tail a000290_list]
%o -- _Reinhard Zumkeller_, Mar 14 2014
%Y Cf. A000463.
%Y Cf. A000578, A000027, A000290.
%Y Cf. A010872.
%K nonn,easy,look
%O 1,4
%A _Mohammad K. Azarian_, Aug 30 2005
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