OFFSET
0,2
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.
FORMULA
Numbers so far appear to equal A052497(n)/8. - Ralf Stephan, Mar 30 2004
a(n) = A(9,n) where A(q,n) is defined in A003787. - Sean A. Irvine, Sep 18 2015
MATHEMATICA
f[m_, n_] := m^(n (n + 1)/2) Product[m^k - 1, {k, 2, n + 1}];
f[9, #] & /@ Range[0, 7] (* Michael De Vlieger, Sep 18 2015 *)
PROG
(Magma) [&*[(9^n - 9^k): k in [0..n-1]]/8: n in [1..10]]; // Vincenzo Librandi, Sep 19 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
a(7) from Sean A. Irvine, Sep 18 2015
STATUS
approved