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A102944 Numbers n such that 10^n + 8*R_n - 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n. 1
1, 16, 22, 28, 34, 90, 2068, 2374, 2854, 3720, 4242, 22666, 29292, 29508 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also numbers n such that (17*10^n-53)/9 is prime.

a(15) > 10^5. - Robert Price, Feb 11 2015

LINKS

Table of n, a(n) for n=1..14.

Makoto Kamada, Prime numbers of the form 188...883.

Index entries for primes involving repunits.

FORMULA

a(n) = A102030(n) + 1.

MATHEMATICA

Do[ If[ PrimeQ[(17*10^n - 53)/9], Print[n]], {n, 0, 10000}]

CROSSREFS

Cf. A002275, A102030.

Sequence in context: A091118 A294125 A064804 * A058901 A059756 A242214

Adjacent sequences:  A102941 A102942 A102943 * A102945 A102946 A102947

KEYWORD

more,nonn,changed

AUTHOR

Robert G. Wilson v, Dec 16 2004

EXTENSIONS

Addition of a(12)-a(14) from Kamada data by Robert Price, Dec 12 2010

STATUS

approved

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Last modified January 22 18:06 EST 2019. Contains 319365 sequences. (Running on oeis4.)