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A102933 Numbers n such that 10^n + 3*R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n. 1
1, 2, 4, 7, 10, 13, 14, 22, 23, 29, 38, 50, 53, 67, 104, 350, 376, 412, 1205, 1835, 2510, 2668, 6097, 8296, 14296, 43369 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also numbers n such that (4*10^n+17)/3 is prime.

LINKS

Table of n, a(n) for n=1..26.

Makoto Kamada, Prime numbers of the form 133...339.

Index entries for primes involving repunits.

FORMULA

a(n) = A102014(n) + 1.

MATHEMATICA

Do[ If[ PrimeQ[(4*10^n + 17)/3], Print[n]], {n, 0, 10000}]

CROSSREFS

Cf. A002275, A102014.

Sequence in context: A007303 A102988 A080137 * A122019 A190279 A186325

Adjacent sequences:  A102930 A102931 A102932 * A102934 A102935 A102936

KEYWORD

more,nonn

AUTHOR

Robert G. Wilson v, Dec 16 2004

EXTENSIONS

Addition of a(25) from Kamada data by Robert Price, Dec 08 2010

a(26) from Erik Branger May 01 2013 by Ray Chandler, Aug 16 2013

STATUS

approved

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Last modified March 26 00:37 EDT 2019. Contains 321479 sequences. (Running on oeis4.)