OFFSET
2,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 2..322
P. De Geest, Repunits and Their Factors
EXAMPLE
Highest and lowest prime factors of 111111 are 3 and 37, so the sixth term is 111.
MATHEMATICA
plh[n_]:=Module[{fi=FactorInteger[FromDigits[PadRight[{}, n, 1]]]}, fi[[1, 1]]fi[[-1, 1]]]; Array[plh, 30, 2] (* Harvey P. Dale, May 04 2021 *)
PROG
(PARI) for(n=2, 20, p=(10^n-1)/9; print1(factor(p)[1, 1]*factor(p)[#factor(p)[, 1], 1], ", ")) \\ Derek Orr, Nov 02 2014
(Python)
from sympy import factorint
A249627_list = [min(fs)*max(fs) for fs in (factorint((10**n-1)//9) for n in range(2, 31))] # Chai Wah Wu, Nov 04 2019
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jacob Vecht, Nov 02 2014
EXTENSIONS
More terms from Derek Orr, Nov 02 2014
STATUS
approved