1,1

Also called repunit primes.

The prime repunits, primes with digital product = 1.

The next term is too large to include: see A004023, A046413.

T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, page 11.

J. Brillhart et al., Factorizations of b^n +- 1. Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 2nd edition, 1985; and later supplements.

Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see p. 60.

T. D. Noe, Table of n, a(n) for n=1..5

J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.

Andy Steward, Prime Generalized Repunits

S. S. Wagstaff, Jr., The Cunningham Project

See A046413 for the number of 1's. Cf. A004023.

Adjacent sequences: A004019 A004020 A004021 this_sequence A004023 A004024 A004025

Sequence in context: A072218 A046844 A066953 this_sequence A083344 A063863 A101364

nonn,nice,bref

njas