A003848 Order of (usually) simple Chevalley group D_2(q), q = prime power.

36, 144, 3600, 3600, 28224, 254016, 129600, 435600, 1192464, 16646400, 5992704, 11696400, 36869184, 60840000, 96589584, 148352400, 221414400, 1071645696, 640494864, 1186113600, 1578631824, 2692364544, 3457440000, 5537145744, 10539075600, 12873171600, 68685926400

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

References

• J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, ATLAS of Finite Groups. Oxford Univ. Press, 1985 [for best online version see https://oeis.org/wiki/Welcome#Links_to_Other_Sites], p. xvi.
• H. S. M. Coxeter and W. O. J. Moser, Generators and Relations for Discrete Groups, 4th ed., Springer-Verlag, NY, reprinted 1984, p. 131.

Links

• Index entries for sequences related to groups.

Crossrefs

Cf. A000961, A003808, A003837, A003850, A003851, A003852, A003853, A003854.

Programs

Mathematica

d[q_, n_] := q^(n*(n-1)) * (q^n-1) * Product[q^(2*k) - 1, {k, 1, n-1}] / GCD[4, q^n-1]; Table[d[q, 2], {q, Select[Range[50], PrimePowerQ]}] (* Amiram Eldar, Jun 24 2025 *)

Formula

a(n) = d(A000961(n+1),2) where d(q,n) is defined in A003837. - Sean A. Irvine, Sep 17 2015