1,2

J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 55, p. 20, Ellipses, Paris 2008.

D. Wells, Curious and interesting numbers, Penguin Books, p. 108

Cf. A000045, A000217.

Sequence in context: A034186 A027499 A152773 this_sequence A033567 A162394 A129212

Adjacent sequences: A039592 A039593 A039594 this_sequence A039596 A039597 A039598

fini,nonn,full

Felice Russo (felice.russo(AT)katamail.com)