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A177999
Largest n digit prime with the most digits equal to 1.
2
7, 11, 911, 8111, 16111, 911111, 1171111, 71111111, 131111111, 1711111111, 31111111111, 311111111111, 5111111111111, 41111111111111, 111151111111111, 5111111111111111, 11111611111111111, 191111111111111111
OFFSET
1,1
COMMENTS
Select first for maximum number of 1's, then take the largest.
In more detail: To get a(n), look at the list of all the n-digit primes. Suppose k is the maximum number of 1's of any number on the list. Throw out any prime on the list that does not contain k 1's. Then a(n) = maximal number that is left on the list. - N. J. A. Sloane, Mar 20 2018
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, May 17 2010
STATUS
approved