
REFERENCES

J.M. De Koninck, Ces nombres qui nous fascinent, Entry 145, p. 50, Ellipses, Paris 2008.
Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see p. 68.
Joe Roberts, "The Lure of the Integers", page 35.
D. Wells, Curious and interesting numbers, Penguin Books, p. 125.
