

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
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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 nearrepdigitrelated 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 A285998
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



