A096497 Prime following n-th repunit.

2, 13, 113, 1117, 11113, 111119, 1111151, 11111117, 111111113, 1111111121, 11111111113, 111111111149, 1111111111139, 11111111111123, 111111111111229, 1111111111111123, 11111111111111119, 111111111111111131, 1111111111111111171, 11111111111111111131, 111111111111111111157, 1111111111111111111189

Offset: 1

Author

Labos Elemer, Jul 09 2004

Keywords

• nonn

Comments

Not equal to A068693: first and 2nd terms differ.

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A068693, A002275.

Programs

Mathematica

Table[NextPrime[(10^n-1)/9], {n, 40}]
Table[NextPrime[FromDigits[PadRight[{},n,1]]],{n,30}] (* Harvey P. Dale, Aug 11 2023 *)

PARI

a(n) = nextprime((10^n-1)/9 + 1); \\ Michel Marcus, May 02 2016

Python

from sympy import nextprime
def A096497(n):
    return nextprime((10**n-1)//9) # Chai Wah Wu, Nov 04 2019

Formula

a(n) = A002275(n) + A096869(n) = A096498(n) + A096499(n).