... case
1
where one distinguishes 4
k
2
(1-
k
2
)
or
(1-
k
2
)/2
k
for
N
respectively odd or even.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
... counterpart
2
We note that
where
f
is the Belyi function of the tetrahedron, see [
33
], p. 376.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Agnes Szanto
2000-05-10