7 lines
194 B
Python
7 lines
194 B
Python
>>> import re
|
|
>>> def isprime(n):
|
|
return not re.match(r'^1?$|^(11+?)\1+$', '1' * n)
|
|
|
|
>>> # A quick test
|
|
>>> [i for i in range(40) if isprime(i)]
|
|
[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37]
|