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A178175 Numbers n such that 10^n - 47 is prime. 0
2, 3, 6, 33, 48, 74, 231, 3206, 4544, 7064, 13634, 41384, 64862, 82790 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next term, if one exists, is >100000. - Robert Price, Apr 25 2011

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99953".

LINKS

Table of n, a(n) for n=1..14.

Makoto Kamada, List of near-repdigit-related prime numbers.

Index entries for primes involving repunits.

EXAMPLE

10^3 - 47 = 953 is a prime number.

MATHEMATICA

m=1000; For[n=1, n<m, If[PrimeQ[10^n-47], Print[n]]; n++ ]

PROG

(PARI) is(n)=ispseudoprime(10^n-47) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A108330, A108328.

Sequence in context: A033689 A018324 A263803 * A129379 A000308 A173501

Adjacent sequences:  A178172 A178173 A178174 * A178176 A178177 A178178

KEYWORD

more,nonn

AUTHOR

Robert Price, Dec 17 2010

EXTENSIONS

a(12:14)=41384,64862,82790 from Robert Price, Apr 25 2011

STATUS

approved

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Last modified September 26 05:09 EDT 2017. Contains 292502 sequences.