

A103088


Numbers n such that 8*10^n + 6*R_n + 3 is prime, where R_n = 11...1 is the repunit (A002275) of length n.


1



1, 3, 17, 19, 33, 39, 169, 453, 611, 883, 1473, 6511, 9647, 21593, 39991, 40157
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OFFSET

1,2


COMMENTS

Also numbers n such that (26*10^n+7)/3 is prime.


LINKS

Table of n, a(n) for n=1..16.
Makoto Kamada, Prime numbers of the form 866...669.
Index entries for primes involving repunits.


FORMULA

a(n) = A101075(n) + 1.


MATHEMATICA

Do[ If[ PrimeQ[(26*10^n + 7)/3], Print[n]], {n, 0, 10000}]


CROSSREFS

Cf. A002275, A101075.
Sequence in context: A038886 A019342 A029473 * A226925 A259772 A082387
Adjacent sequences: A103085 A103086 A103087 * A103089 A103090 A103091


KEYWORD

more,nonn


AUTHOR

Robert G. Wilson v, Jan 19 2005


EXTENSIONS

a(14)a(16) from Kamada data by Robert Price, Dec 14 2010


STATUS

approved



