Intended for: September 18, 2011
Timetable
- First draft entered by Alonso del Arte on September 11, 2011 ✓
- Draft reviewed by Daniel Forgues on September 18, 2012 ✓, September 18, 2018 ✓
- Draft to be approved by August 18, 2011
The line below marks the end of the <noinclude> ... </noinclude> section.
A020988:
| (4 n − 1) = 2 = 2 4 k = 2 2k +1, n ≥ 0 |
.
-
{ 0, 2, 10, 42, 170, 682, 2730, 10922, ... }
These are singly even numbers, i.e.
, thus with all
2s
base 4 representation
2222...22224 (in the case of
0 we have zero
2s, which gives the impractical empty string more conveniently represented by showing a leading
0). These numbers are also the sum of distinct powers of
2 that are not powers of
4 (their
binary representations have every odd indexed bit set to
1). In
hexadecimal, these numbers are either all
As or an initial
2 followed by all
As. For example,
71582788216 in binary is
1010101010101010101010101010102 and in hexadecimal
2AAAAAAA16.
