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Template:Sequence of the Day for March 8

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Intended for: March 8, 2013

Timetable

  • First draft entered by Alonso del Arte on February 16, 2012
  • Draft reviewed by Daniel Forgues on March 3, 2016
  • Draft to be approved by February 8, 2013

Yesterday's SOTD * Tomorrow's SOTD

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



A001316: Gould’s sequence:
a (n) =
n

k  = 0
 [(  nk  ) mod 2]
.
{ 1, 2, 2, 4, 2, 4, 4, 8, 2, 4, 4, 8, 4, 8, 8, 16, 2, ... }
Essentially this counts how many odd entries there are in row
n
of Pascal’s triangle, and like the sequence of row sums, this sequence also consists entirely of powers of 2. Robert Wilson noticed that the first occurrence of
2k
is when
n = 2k  −  1
, while Benoit Cloitre discovered that
a (n)
is the highest power of 2 dividing
(  2 nn  )
.