login
This site is supported by donations to The OEIS Foundation.

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A120533 Primes having a prime number of digits. 1
11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Before the 20th century, this sequence would have contained the numbers 1,2,3,5,7; see A008578.

LINKS

Table of n, a(n) for n=1..57.

EXAMPLE

10007 is a 5-digit prime and so belongs to the sequence.

PROG

(PARI) g(n) = forprime(x=11, n, if(isprime(length(Str(x))), print1(x", ")))

(PARI) forprime(p=2, 5, forprime(q=10^(p-1), 10^p, print1(q", "))) \\ Charles R Greathouse IV, Oct 04 2011

CROSSREFS

Cf. A000040, A124888.

Sequence in context: A096489 A008364 A140461 * A226108 A095862 A125845

Adjacent sequences:  A120530 A120531 A120532 * A120534 A120535 A120536

KEYWORD

base,nonn

AUTHOR

Cino Hilliard, Aug 06 2006

EXTENSIONS

Edited by N. J. A. Sloane at the suggestion of Andrew Plewe, May 21 2007

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified July 24 15:58 EDT 2014. Contains 244896 sequences.