1. [BC] Boklan, K. D., and Conway, J. H.: Expect at most one billionth of a new Fermat Prime! arXiv e-prints, http://arxiv.org/abs/1605.01371 .
2. [CMP] Crandall, R., Mayer, E., and Papadopoulos, J.: The Twenty-Fourth Fermat Number is composite. Math. of Computation 72 (2002), 1555–1572.
3. [DK] Dubner, H., and Keller, W.: Factors of generalized Fermat numbers. Math. of Computation 64 (1995), 397–405.
4. [HW] Hardy, G. H., and Wright, E. M.: An Introduction to the Theory of Numbers [6th ed. (2008)] Oxford University Press.
5. [NDE] Private email communication to the first author, January 3, 2014.