Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A108966
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A108966 Numbers n such that repunit(n) concatenated with its 10's complement is prime; or numbers n such that (1+7*10^n+100^n)/9 is prime. +0
1
1, 5, 16, 36, 61, 149, 725, 1104, 1276, 1289, 8575 (list; graph; listen)
OFFSET

1,2

COMMENT

Larger values are only Fermat and Lucas PRPs.

EXAMPLE

a(2)=5 because 10^5-11111 = 88889 and 1111188889 is prime.

CROSSREFS

Cf. A002275.

Sequence in context: A096941 A098404 A077415 this_sequence A072333 A055232 A001210

Adjacent sequences: A108963 A108964 A108965 this_sequence A108967 A108968 A108969

KEYWORD

base,hard,more,nonn

AUTHOR

Jason Earls (zevi_35711(AT)yahoo.com), Jul 26 2005

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 25 20:09 EST 2009. Contains 167514 sequences.


AT&T Labs Research