Cullen Primes: Definition and Status
Cullen primes are Cullen numbers that are prime and of the form Cn = n*2n+1. Woodall numbers are related (Wn = n*2n-1) and are sometimes called Cullen numbers of the second kind.
Cn is prime for n = 1, 141, 4713, 5795, 6611, 18496, 32292, 32469, 59656, 90825, 262419, 361275, 481899 and for no other n with n < 412,000; Chris Caldwell maintains the top 20 Cullen Page.
A table of ranges of exponents that have already been tested or are reserved/available for current testing for Cullen primes is available.
A list of contributors to the Cullen project are here.
Woodall primes (Wn = n*2n-1) are on another page.
To reserve a free range of n for one of the numbers above, check the most recent reserved values of n also and then click on the link on that page to reserve your range in Proth Search