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A225936
Number of conjugacy classes in simply connected Chevalley group E_7(q) as q runs through the prime powers.
1
531, 5052, 24553, 107833, 999759, 2447517, 5494392, 21711067, 68562129, 287617189, 437995549, 946912755, 3567919999, 6370211253, 10880553708, 17891119105, 28464383127, 35505127221, 97650322329, 199757104357, 278459342139, 517897029319, 692671751805
OFFSET
1,1
FORMULA
Let q be the n-th prime power. Then, a(n) is
q^7 + q^6 + 2q^5 + 4q^4 + 10q^3 + 15q^2 + 25q + 21 if q == 0 (mod 2);
q^7 + q^6 + 2q^5 + 7q^4 + 17q^3 + 35q^2 + 70q + 99 if q == 0 (mod 3);
q^7 + q^6 + 2q^5 + 7q^4 + 17q^3 + 35q^2 + 71q + 103 otherwise.
PROG
(Sage) def A225936(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 7*q^4 + 17*q^3 + 35*q^2 + 70*q + 99 if q%3==0 else 7*q^4 + 17*q^3 + 35*q^2 + 71*q + 103)
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric M. Schmidt, May 21 2013
STATUS
approved