%I #24 Feb 26 2024 14:37:10
%S 1,1,205,5905,61681,375601,1634221,5649505,16519105,42521761,99009901,
%T 212601841,427016305,810932305,1468297741,2551550401,4278255361,
%U 6951703105,10986053005,16936647121,25536159601,37737287281,54762727405,78163228705,109884542401
%N a(n) = n^8 - n^6 + n^4 - n^2 + 1.
%C a(n) = Phi_20(n) where Phi_k(x) is the k-th cyclotomic polynomial.
%H Harry J. Smith, <a href="/A060892/b060892.txt">Table of n, a(n) for n=0..1000</a>
%H <a href="/index/Cy#CyclotomicPolynomialsValuesAtX">Index to values of cyclotomic polynomials of integer argument</a>
%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (9,-36,84,-126,126,-84,36,-9,1).
%F G.f.: (1-8*x+232*x^2+4012*x^3+15958*x^4+15832*x^5+4096*x^6+196*x^7+x^8)/ (1-x)^9. [_Colin Barker_, Apr 22 2012]
%p A060892 := proc(n)
%p numtheory[cyclotomic](20,n) ;
%p end proc:
%p seq(A060892(n),n=0..20) ; # _R. J. Mathar_, Feb 11 2014
%t Cyclotomic[20, Range[0, 30]] (* _Paolo Xausa_, Feb 26 2024 *)
%o (PARI) a(n) = n^8 - n^6 + n^4 - n^2 + 1; \\ _Harry J. Smith_, Jul 14 2009
%K nonn,easy
%O 0,3
%A _N. J. A. Sloane_, May 05 2001