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A216346
Primes of the form n*10^n - 1
0
199, 2999, 799999999, 1099999999999, 14999999999999999, 38999999999999999999999999999999999999999, 59999999999999999999999999999999999999999999999999999999999999, 71999999999999999999999999999999999999999999999999999999999999999999999999
OFFSET
1,1
COMMENTS
The corresponding n are in A059671.
a(9) = 769999999….999999 contains 79 digits.
a(10) = 1169999999….999999 contains 120 digits.
MATHEMATICA
lst={}; Do[ p=n*10^n- 1; If[PrimeQ[p], AppendTo[lst, p]], {n, 0, 60}]; lst
Select[Table[n*10^n-1, {n, 100}], PrimeQ] (* Harvey P. Dale, Sep 17 2023 *)
CROSSREFS
Cf. A059671.
Sequence in context: A052188 A086977 A324628 * A289819 A195523 A163712
KEYWORD
nonn
AUTHOR
Michel Lagneau, Sep 04 2012
STATUS
approved