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!)
A229908 The least prime that has at least n embedded primes, reading forward and backward. 1
2, 13, 13, 37, 113, 113, 137, 1237, 1373, 1733, 1733, 11317, 11731, 12713, 19973, 91733, 113173, 113371, 113371, 173347, 991733, 1123379, 1134673, 1137991, 1237199, 2333719, 7433719, 11133719, 11399173, 11399173, 11791733, 37914713, 97433719, 113217397, 113217397, 113337199, 113337199, 113337199, 1113371999, 1113371999, 1113991733, 1139917321, 1139917321, 1139917333 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Results of my search up to 2^32.

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..65 (terms < 3.5*10^12)

C. Rivera, Puzzle 724. Extending the OEIS sequence A229908

EXAMPLE

Example: a(8) = 1237 because there are the following eight embedded primes: 1237, 2, 23, 3, 37, 7 and 73, 7321.

CROSSREFS

Cf. A039993, A039997.

Sequence in context: A037055 A065584 A153651 * A320339 A075032 A032932

Adjacent sequences:  A229905 A229906 A229907 * A229909 A229910 A229911

KEYWORD

nonn,base,hard

AUTHOR

Carlos Rivera, Dec 19 2013

EXTENSIONS

Missing a(19) from Giovanni Resta, Jan 25 2014

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 January 28 03:49 EST 2020. Contains 331317 sequences. (Running on oeis4.)