%I #41 Dec 16 2016 03:06:43
%S 1,3,105,11025,5439105,11193473025,89273960290305,2926331900465537025,
%T 380704455834655419367425,200503685263248842050957082625,
%U 418936006416927720918846481798529025,3516831926000321799217446305276779638554625
%N Number of semisimple invertible n X n matrices over GF(2).
%C Fulman shows that the ratio a(n)/A002884(n) converges to Product_{r>=1, r == 0,2,3 mod 5} (1-2^(-(r-1)))/(1-2^(-r)).
%H Jason Fulman, <a href="http://arxiv.org/abs/math/9712239">Cycle Indices for the Finite Classical Groups</a>, J. Group Thy., v. 2, 1999, 251-289.
%e a(2) = 3, the matrices are [[1,0],[0,1]], [[0,1],[1,1]], [[1,1],[1,0]].
%Y Cf. A225371 (every semisimple matrix over GF(2) is a square of another matrix).
%K nonn,nice
%O 1,2
%A _Victor S. Miller_, Jun 04 2013