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A110933 Integers n such that 3*10^n + 71 is a prime number. 0
1, 4, 7, 16, 19, 190, 227, 235, 283, 319, 1655, 3955, 10666, 30724 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "30071".

a(15) > 10^5. - Robert Price, Jan 22 2017

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

n = 7 is a member because: 3*10^7 + 71 = 3*10000000 + 71 = 30000000 + 71 = 30000071, which is prime.

PROG

(PARI) isok(n) = isprime(3*10^n+71); \\ Michel Marcus, Jan 22 2017

CROSSREFS

Cf. A049054, A088274, A088275, A095688, A107083, A108049, A108050, A108052, A108054.

Sequence in context: A212062 A256926 A101534 * A067398 A054599 A229917

Adjacent sequences:  A110930 A110931 A110932 * A110934 A110935 A110936

KEYWORD

more,nonn

AUTHOR

Julien Peter Benney (jpbenney(AT)ftml.net), Oct 04 2005

EXTENSIONS

a(13) from Ray Chandler, Dec 23 2010

Prepended a(1)=1 by Robert Price, Jan 22 2017

a(14) from Robert Price, Jan 22 2017

STATUS

approved

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Last modified February 24 11:51 EST 2017. Contains 282573 sequences.