login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A103071 Numbers n such that 8*10^n + R_n + 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n. 1
1, 10, 24, 199, 745, 7753, 17938, 21319, 24948, 26119, 29454, 51889, 62824, 88105 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also numbers n such that (73*10^n+17)/9 is prime.

a(15) > 10^5. - Robert Price, Oct 16 2015

LINKS

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

Makoto Kamada, Prime numbers of the form 811...113.

Index entries for primes involving repunits.

FORMULA

a(n) = A101058(n) + 1.

MATHEMATICA

Do[ If[ PrimeQ[(73*10^n + 17)/9], Print[n]], {n, 0, 10000}]

CROSSREFS

Cf. A002275, A101058.

Sequence in context: A261807 A135285 A235940 * A264296 A265150 A057462

Adjacent sequences:  A103068 A103069 A103070 * A103072 A103073 A103074

KEYWORD

more,nonn

AUTHOR

Robert G. Wilson v, Jan 19 2005

EXTENSIONS

a(7)-a(11) from Kamada data by Robert Price, Dec 14 2010

a(12)-a(14) from Robert Price, Oct 16 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 26 08:33 EST 2020. Contains 332277 sequences. (Running on oeis4.)