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G.f.: Product((1+x^i)/(1-x^i),i=1..n-1)/(1-x^n), with n = 5.
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%I #23 Apr 26 2021 14:28:25

%S 1,2,4,8,14,23,36,54,78,110,151,202,266,344,438,551,684,840,1022,1232,

%T 1473,1748,2060,2412,2808,3251,3744,4292,4898,5566,6301,7106,7986,

%U 8946,9990,11123,12350,13676,15106,16646,18301,20076,21978,24012,26184,28501,30968

%N G.f.: Product((1+x^i)/(1-x^i),i=1..n-1)/(1-x^n), with n = 5.

%C Poincaré series [or Poincare series] (or Molien series) for H^*(O_5(q); F_2).

%D A. Adem and R. J. Milgram, Cohomology of Finite Groups, Springer-Verlag, 2nd. ed., 2004; p. 233.

%H Harvey P. Dale, <a href="/A091773/b091773.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,2,-3,4,-4,3,-2,3,-3,1).

%F G.f.: -(x^2-x+1)*(x^4+1) / ((x-1)^5*(x^2+x+1)*(x^4+x^3+x^2+x+1)). - _Colin Barker_, Jan 31 2013

%F a(n) = 3*a(n-1)-3*a(n-2)+2*a(n-3)-3*a(n-4)+4*a(n-5)-4*a(n-6)+3*a(n-7)-2*a(n-8)+3*a(n-9)-3*a(n-10)+a(n-11). - _Wesley Ivan Hurt_, Apr 26 2021

%t LinearRecurrence[{3,-3,2,-3,4,-4,3,-2,3,-3,1},{1,2,4,8,14,23,36,54,78,110,151},50] (* _Harvey P. Dale_, Feb 17 2018 *)

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Mar 18 2004