A116692 Primes with only one distinct decimal digit. Also called repunit primes or repdigit primes.

2, 3, 5, 7, 11, 1111111111111111111, 11111111111111111111111

Offset

1,1

Comments

Primes in A010785 (repdigit numbers). Union of single-digit primes and A004022 (repunit primes). A004023 shows that the next term has 317 1's. The Mersenne primes (A000668) are the binary analog (i.e., bits are all 1's).

References

Clifford A. Pickover, A Passion for Mathematics (2005) at 60, 297.

Links

Table of n, a(n) for n=1..7.

Crossrefs

A004022 is a subsequence.

Cf. A004023, A010785, A000668.

A subsequence of A055387, but not of A225053.

Sequence in context: A091689 A046482 A046941 * A114983 A118950 A344451

Adjacent sequences: A116689 A116690 A116691 * A116693 A116694 A116695

Keyword

base,easy,nonn

Author

Rick L. Shepherd, Feb 22 2006

Extensions

Reference provided by Harvey P. Dale, Apr 19 2014

Definition expanded by N. J. A. Sloane, Jan 22 2023

Status

approved