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A093400
Primes of the form 10*R_k + 9, where R_k is the repunit (A002275) of length k.
1
19, 11119, 111119, 11111119, 11111111111111119, 11111111111111111111111111111111111111111111111119
OFFSET
1,1
COMMENTS
The next term has 684 digits. - Harvey P. Dale, Dec 11 2013
MATHEMATICA
Select[Table[FromDigits[PadLeft[{9}, n, 1]], {n, 1000}], PrimeQ] (* Harvey P. Dale, Dec 11 2013 *)
CROSSREFS
Cf. A056659 (corresponding k and count of digits 1 in a(n)).
Sequence in context: A270972 A260005 A276739 * A265169 A174306 A270069
KEYWORD
nonn
AUTHOR
Rick L. Shepherd, Mar 28 2004
STATUS
approved