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Template:Sequence of the Day for January 3

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Intended for: January 3, 2012

Timetable

  • First draft entered by Alonso del Arte on October 30, 2011
  • Draft reviewed by Daniel Forgues on November 6, 2011
  • Draft to be approved by December 3, 2011
Yesterday's SOTD * Tomorrow's SOTD

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



A000265: Largest odd divisor of
n
.
{ 1, 1, 3, 1, 5, 3, 7, 1, ... }
Obviously
a (n) = 1
only when
n
is a power of
2
and
a(n) = n
only when
n
is an odd noncomposite number. Somewhat less obviously, this is the numerator of
n
2n −1
and the denominator of
2n −1
n
.
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