A178580 - OEIS

%I #11 Dec 06 2021 15:04:26

%S 1,0,0,1,0,0,0,0,0,1,0,1,1,0,1,1,0,1,1,0,2,0,0,2,1,0,3,1,1,2,0,1,2,0,

%T 1,3,0,2,2,0,2,2,0,3,1,0,2,1,0,2,1,1,3,0,1,2,0,0,2,0,1,1,0,1,1,0,1,1,

%U 0,1,0,0,0,0,0,1,0,0,1

%N Expansion of the polynomial (1+x^3)*(1+x^9)*(1+x^11)*(1+x^15)*(1+x^17)*(1+x^23).

%C This is the Poincaré polynomial for the Lie group E_6.

%D Borel, A. and Chevalley, C., The Betti numbers of the exceptional groups, Mem. Amer. Math. Soc. 1955, no. 14, pp 1-9.

%t CoefficientList[Series[(1+x^3)(1+x^9)(1+x^11)(1+x^15)(1+x^17)(1+x^23),{x,0,120}],x] (* _Harvey P. Dale_, Dec 06 2021 *)

%K nonn,fini,full,easy

%O 0,21

%A _N. J. A. Sloane_, Dec 24 2010