Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A102974
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A102974 Numbers n such that 3*10^n + 6*R_n - 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n. +0
2
0, 1, 6, 11, 13, 19, 23, 67, 108, 118, 176, 673, 780, 1088, 1219, 1656, 6245 (list; graph; listen)
OFFSET

1,3

COMMENT

Also numbers n such that (11*10^n-17)/3 is prime.

LINKS

Makoto Kamada, Factorizations of 366...661.

Index entries for primes involving repunits.

MATHEMATICA

Do[ If[ PrimeQ[(11*10^n-17)/3], Print[n]], {n, 0, 10000}]

CROSSREFS

Sequence in context: A175021 A046953 A121765 this_sequence A154293 A068308 A163871

Adjacent sequences: A102971 A102972 A102973 this_sequence A102975 A102976 A102977

KEYWORD

more,nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 17 2004

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 21 21:21 EST 2009. Contains 167310 sequences.


AT&T Labs Research