Given an integer ,
the Payam number
is the smallest positive odd integer
such that for every positive integer
, the number
is not divisible by any primes
such that the multiplicative
order of 2
is less than or equal to
.
Payam numbers are good candidates for searching for Proth
primes, i.e., primes of the form
, as well as primes of the form
.
The first few values of
for
, 3, ... are 3, 9, 15, 105, 105, 105,
105, 105, 165, 165, 75075, ... (OEIS A083556),
and the first few values of
are 3, 3, 45, 45, 45, 45, 45, 45, 45, 2145, ... (OEIS
A083391).