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A105431 Primes of form R_n + 2 {= (10^n + 17)/9}, R_n being the n-th repunit, i.e., primes consisting of a string of 1's followed by a terminal 3. 0
3, 13, 113, 1113, 111113, 1111111113, 111111111113, 1111111111111111111111113, 1111111111111111111111111111111111111111111111111111111111111111111111111111111111113 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For the associated positive values n see A097683.

LINKS

Table of n, a(n) for n=1..9.

Makoto Kamada, Prime numbers of the form 11...113.

Index entries for primes involving repunits

CROSSREFS

Cf. A098406.

Sequence in context: A181083 A090537 A063269 * A062447 A053583 A077713

Adjacent sequences:  A105428 A105429 A105430 * A105432 A105433 A105434

KEYWORD

nonn

AUTHOR

Lekraj Beedassy, Apr 08 2005

STATUS

approved

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Last modified September 28 05:33 EDT 2020. Contains 337392 sequences. (Running on oeis4.)