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A287351 Numbers k such that (10^k*361 - 163)/9 is prime (k > 0). 0
1, 3, 9, 15, 27, 37, 165, 207, 897, 5761, 16753, 17995, 96567 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(14) > 10^5. - Robert Price, Oct 31 2017

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

If k = 1 then (10^1*361 - 163)/9 = 383 (prime), so 1 is a term.

If k = 9 then (10^9*361 - 163)/9 = 40111111093 (prime), so 9 is a term.

MATHEMATICA

ParallelMap[ If[ PrimeQ[ (10^# 361-163)/9], #, Nothing] &, Range[6000]]

CROSSREFS

Cf. A247643.

Sequence in context: A087031 A089632 A247643 * A256388 A082897 A339886

Adjacent sequences:  A287348 A287349 A287350 * A287352 A287353 A287354

KEYWORD

nonn,hard,more

AUTHOR

Mikk Heidemaa, May 23 2017

EXTENSIONS

a(13) from Robert Price, Oct 31 2017

STATUS

approved

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Last modified October 22 18:45 EDT 2021. Contains 348175 sequences. (Running on oeis4.)