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Template:Sequence of the Day for March 26

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Intended for: March 26, 2013

Timetable

  • First draft entered by Daniel Forgues and Alonso del Arte on February 2, 2013
  • Draft reviewed by Daniel Forgues on February 4, 2013 ✓, March 26, 2014 ✓, March 25, 2018
  • Draft to be approved by February 26, 2013
Yesterday's SOTD * Tomorrow's SOTD

The line below marks the end of the <noinclude> ... </noinclude> section.



A033308: Decimal expansion of the Copeland–Erdős constant: concatenate the base 10 representations of the prime numbers
pi
as a number in the unit interval,
i  = 1
  
pi 10  −  
i

j  = 1
( 1 +
⌊  log10 pj ⌋
 )
=
i  = 1
  
pi 10  − 
i +
i

j  = 1
⌊  log10 pj ⌋
,

or

i  = 1
  
pi 10  −  
i

j  = 1
⌈ log10 ( 1 + pj )⌉
 ,

giving

0.23571113171923293137...

In 1946, A. H. Copeland and Paul Erdős proved that this is a normal number.

March 26, 2013 marks the 100 th anniversary of the birth of Paul Erdős.

See A191232 for the binary expansion of the “binary” Copeland–Erdős constant.