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A177866 Numbers n such that 10^n - 69 is prime. 1
2, 4, 6, 7, 8, 14, 20, 110, 138, 140, 145, 300, 390, 1484, 3194, 3300, 3950, 4986, 5574, 5630, 5874, 8866, 11390, 45130, 86110 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The next term, if it exists, is > 100000.
See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99931".
LINKS
EXAMPLE
10^6 - 69 = 999931 which is a prime number.
MATHEMATICA
m=1000; For[n=1, n<m, If[PrimeQ[10^n-69], Print[n]]; n++ ]
PROG
(PARI) is(n)=ispseudoprime(10^n-69) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A015924 A096750 A088458 * A065853 A048284 A026516
KEYWORD
more,nonn
AUTHOR
Robert Price, Dec 28 2010
EXTENSIONS
a(24-25)=45130,86110 from Robert Price, May 29 2011
STATUS
approved

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Last modified March 28 13:42 EDT 2024. Contains 371254 sequences. (Running on oeis4.)