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n followed by n^3 followed by n^2 followed by n^4.
1

%I #27 Jul 20 2024 10:59:07

%S 1,1,1,1,2,8,4,16,3,27,9,81,4,64,16,256,5,125,25,625,6,216,36,1296,7,

%T 343,49,2401,8,512,64,4096,9,729,81,6561,10,1000,100,10000,11,1331,

%U 121,14641,12,1728,144,20736,13,2197,169,28561,14,2744,196,38416,15,3375

%N n followed by n^3 followed by n^2 followed by n^4.

%H <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 5, 0, 0, 0, -10, 0, 0, 0, 10, 0, 0, 0, -5, 0, 0, 0, 1).

%F a(n) = (2*n+3-(-1)^n+2*(-1)^((2*n+5-(-1)^n)/4))*(n^3+4*n^2+32*n+96+(n^3+4*n^2-64)*(-1)^n-(n^3-4*n^2-64)*(-1)^((2*n+5-(-1)^n)/4)+(n^3-4*n^2-32*n+32)*(-1)^((2*n+7+(-1)^n)/4))/2048. - _Luce ETIENNE_, Sep 01 2016

%F From _Chai Wah Wu_, Jan 11 2020: (Start)

%F a(n) = 5*a(n-4) - 10*a(n-8) + 10*a(n-12) - 5*a(n-16) + a(n-20) for n > 20.

%F G.f.: x*(-x^15 - x^14 + x^13 + x^12 - 11*x^11 + x^10 + 3*x^9 - 3*x^8 - 11*x^7 + x^6 - 3*x^5 + 3*x^4 - x^3 - x^2 - x - 1)/((x - 1)^5*(x + 1)^5*(x^2 + 1)^5). (End)

%t Table[{n, n^3, n^2, n^4}, {n, 1, 15}] // Flatten (* _Jean-François Alcover_, Sep 01 2016 *)

%o (Magma) &cat[[n,n^3,n^2,n^4]: n in [1..15]]; // _Bruno Berselli_, Sep 01 2016

%Y Cf. A000463, A109588, A109594.

%K nonn

%O 1,5

%A _Mohammad K. Azarian_, Sep 02 2005