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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 29 04:06 EDT 2020. Contains 337420 sequences. (Running on oeis4.)