The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A213072 Smallest number whose decimal expansion is a concatenation of two primes in n different ways. 1
 22, 237, 2337, 29397, 739397, 23932917, 1997771997, 79279391397 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(9) <= 4999363379397. - Donovan Johnson, Jun 17 2012 LINKS EXAMPLE a(3) = 2337 because 2337 is the smallest number that can be separated into two primes in three different ways: 2 and 337, 23 and 37, 233 and 7. CROSSREFS Sequence in context: A003205 A037268 A091783 * A159649 A046499 A126903 Adjacent sequences: A213069 A213070 A213071 * A213073 A213074 A213075 KEYWORD nonn,base AUTHOR Claudio Meller, Jun 04 2012 EXTENSIONS a(5)-a(6) from David W. Wilson, Jun 04 2012 a(7)-a(8) from Donovan Johnson, Jun 16 2012 STATUS approved

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

Last modified December 4 02:16 EST 2022. Contains 358544 sequences. (Running on oeis4.)