cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A225936 Number of conjugacy classes in simply connected Chevalley group E_7(q) as q runs through the prime powers.

Original entry on oeis.org

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

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Author

Eric M. Schmidt, May 21 2013

Keywords

Crossrefs

Programs

  • 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)

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.