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A093163 Primes of the form 40*R_k + 3, where R_k is the repunit (A002275) of length k. 2
3, 43, 443, 444443, 444444443, 444444444443, 444444444444444444444444444443, 44444444444444444444444444444443 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Primes of the form (4*10^k - 13)/9; the next term a(9) is a 183-digit number. - Vincenzo Librandi, Nov 16 2010
LINKS
MATHEMATICA
f[n_] := (4*10^n-13)/9; Select[f[Range[50]], PrimeQ] (* Amiram Eldar, Nov 23 2018 *)
Select[Table[FromDigits[PadLeft[{3}, n, 4]], {n, 40}], PrimeQ] (* Harvey P. Dale, Dec 19 2022 *)
CROSSREFS
Cf. A056661 (corresponding k), A173770.
Sequence in context: A036940 A099664 A173770 * A199020 A211959 A283514
KEYWORD
nonn
AUTHOR
Rick L. Shepherd, Mar 26 2004
STATUS
approved

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Last modified March 28 16:34 EDT 2024. Contains 371254 sequences. (Running on oeis4.)