

A096254


Numbers n such that 5*10^n + 3 is prime.


2



1, 2, 3, 8, 18, 20, 31, 42, 103, 175, 181, 531, 706, 1077, 1177, 1552, 19737, 32197, 51508, 58275, 62233, 90033
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OFFSET

1,2


COMMENTS

a(23) > 2*10^5.  Robert Price, Aug 03 2015


LINKS

Table of n, a(n) for n=1..22.
Makoto Kamada, Prime numbers of the form 500...003.
Sabin Tabirca and Kieran Reynolds, Lacunary Prime Numbers.


FORMULA

a(n) = A101568(n) + 1.


EXAMPLE

1, 2 and 3 are in the list because 53, 503 and 5003 are all prime.
500000003 (5*10^8 + 3) is the next similar prime, so 8 is the next term in the sequence.


MATHEMATICA

Do[ If[ PrimeQ[5*10^n + 3], Print[n]], {n, 10000}] (* Robert G. Wilson v, Aug 13 2004 *)


PROG

(PARI) is(n)=isprime(5*10^n+3) \\ Charles R Greathouse IV, Sep 27 2016


CROSSREFS

Cf. A101568.
Sequence in context: A101182 A009207 A290878 * A091765 A036746 A232165
Adjacent sequences: A096251 A096252 A096253 * A096255 A096256 A096257


KEYWORD

more,nonn


AUTHOR

Carl R. White, Aug 10 2004


EXTENSIONS

a(12)a(16) from Robert G. Wilson v, Aug 13 2004
a(17)a(22) from Kamada data by Robert Price, Dec 09 2010


STATUS

approved



