

A108054


Integers n such that 10^n+49 is prime.


27



1, 2, 3, 5, 8, 17, 24, 32, 65, 66, 67, 79, 83, 98, 152, 260, 781, 1225, 1777, 2023, 2411, 3469, 5347, 10646, 11335, 13989, 14792, 16731, 19015, 29471, 39187, 41456, 80883
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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 "10049".


LINKS

Table of n, a(n) for n=1..33.
Makoto Kamada, List of nearrepdigitrelated prime numbers.
Index entries for primes involving repunits.


EXAMPLE

n = 8 ==> 10^8+49 = 100000049, which is prime.


MATHEMATICA

a={}; Do[p=10^n+49; If[PrimeQ[p], AppendTo[a, n]], {n, 0, 10^3, 1}]; a (* Vladimir Joseph Stephan Orlovsky, Jul 17 2008 *)


PROG

(PARI) for(n=1, 1e4, if(ispseudoprime(10^n+49), print1(n", "))) \\ Charles R Greathouse IV, Jul 25 2011


CROSSREFS

Cf. A049054, A088274, A088275, A095688.
Sequence in context: A030034 A093000 A122630 * A123612 A077177 A303874
Adjacent sequences: A108051 A108052 A108053 * A108055 A108056 A108057


KEYWORD

more,nonn


AUTHOR

Julien Peter Benney (jpbenney(AT)ftml.net), Jun 02 2005


EXTENSIONS

a(23) from Ray G. Opao, Dec 13 2006
a(24)a(31) from Robert Price, May 28 2010
Edited by Ray Chandler, Dec 23 2010
a(32) from Robert Price, Dec 27 2010
a(33) from Robert Price, Mar 03 2011


STATUS

approved



