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Template:Sequence of the Day for December 3

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Intended for: December 3, 2011

Timetable

  • First draft entered by Alonso del Arte on November 29, 2011 (based on a remark from Franz Vrabec) ✓
  • Draft to be reviewed by October 3, 2011
  • Draft to be approved by November 3, 2011
Yesterday's SOTD * Tomorrow's SOTD

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



A076512 /A109395:
ϕ (n )
n
=
ω (n)

i  = 1
(1  − 
1
pi
  )
, where
ω (n)
is the number of distinct prime factors function.
{1,
1
2
 ,
2
3
 ,
1
2
 ,
4
5
 ,
1
3
 ,
6
7
 ,
1
2
 , }
The denominator is
pω (n)
(the greatest prime factor) if and only if for every
j < ω (n)
, there is a
k < ω (n)
such that
pj ∣ (  pk  −  1)
.