,
,
,
, etc., and even to guess the
general pattern of such occurences. Such results can usually be proved by the method
of [3]. That is, one guesses the expansion
of
, verifies that this purported expansion is a legitimate expansion of
a beta number
according to Parry's criterion, computes the characteristic
polynomial
of
by (1.2), and verifies that
is divisible by
,
the minimal polynomial of
. For example, here are some simple cases:
Letbe a Salem number of degree 6 with minimal polynomial
given by (2.1). Then
if and only if
and
and
.
Letbe a Salem number of degree 6 with minimal polynomial
given by (2.1). Then
if and only if
, where A,B and C are positive integers satisfying
,
,
with the further condition that if A + B - 1 = C, then A = C and B = 1.
Letbe a Salem number of degree 6 for which
![]()
for some
. Then
.
Remark 4.1 The condition in Proposition 4.3 is only a sufficient condition
for
. There are many other occurrences of
besides the ones
described here.