[seqfan] Re: The number of orbits of triples of (1, 2, ..., n) under the action of the dihedral group of order 2n

[L. Edson Jeffery]

>How did you arrive at this?


Based on your conjectured (Maple) g.f., taking the inverse Z transform of

x*(x^3+2x^2-3x+2)/((x+1)*(x-1)^3)

to get what turned out to be essentially Colin's formula for a(n), I just
played around with it a bit to get separate expressions for odd and even n
that, if true, happen to already be in the database. Otherwise, not much
help with regards to a geometric interpretation.

Ed Jeffery