mersenne_primes
Ptolemy DCLVIII
(
2
^n)-1
when
are
prime
(
2
^2)-1 =
3
(
2
^3)-1 =
7
(
2
^5)-1 =
31
(
2
^7)-1 = 127
[ (
2
^6)-1 = 63 =
7
x
9
]
[
this
is
a
mersenne_number ]
[
but
not
a
mersenne_prime ]
061204
