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A225937 Number of conjugacy classes in adjoint Chevalley group E_7(q) as q runs through the prime powers.

%I A225937 #8 May 22 2013 20:34:38
%S A225937 531,4569,24553,105644,992834,2447517,5477205,21674822,68494004,
%T A225937 287617189,437805224,946620206,3567305234,6369359984,10879403385,
%U A225937 17889596996,28462405562,35505127221,97646355404,199751157632,278452165094,517886829194,692659723976
%N A225937 Number of conjugacy classes in adjoint Chevalley group E_7(q) as q runs through the prime powers.
%H A225937 Eric M. Schmidt, <a href="/A225937/b225937.txt">Table of n, a(n) for n = 1..1000</a>
%H A225937 Frank Luebeck, <a href="http://www.math.rwth-aachen.de/~Frank.Luebeck/chev/nrclasses/nrclasses.html">Numbers of Conjugacy Classes in Finite Groups of Lie Type</a>.
%F A225937 Let q be the n-th prime power. Then, a(n) is
%F A225937 q^7 + q^6 + 2q^5 + 4q^4 + 10q^3 + 15q^2 + 25q + 21 if q == 0 (mod 2);
%F A225937 q^7 + q^6 + 2q^5 + 5q^4 + 13q^3 + 24q^2 + 46q + 57 if q == 0 (mod 3);
%F A225937 q^7 + q^6 + 2q^5 + 5q^4 + 13q^3 + 24q^2 + 47q + 59 otherwise.
%o A225937 (Sage) def A225937(q) : return q^7 + q^6 + 2*q^5 + (4*q^4 + 10*q^3 + 15*q^2 + 25*q + 21 if q%2==0 else 5*q^4 + 13*q^3 + 24*q^2 + 46*q + 57 if q%3==0 else 5*q^4 + 13*q^3 + 24*q^2 + 47*q + 59)
%Y A225937 Cf. A188161, A224790, A225928 - A225938.
%K A225937 nonn
%O A225937 1,1
%A A225937 _Eric M. Schmidt_, May 21 2013