OFFSET
0,2
COMMENTS
The ones in the binary expansion of n encode the Fermi-Dirac factors of a(n).
The following table gives the rank of the bit corresponding to the Fermi-Dirac factor p^2^k:
...
7| 6
5| 3 7
3| 1 4 8
2| 0 2 5 9
---+--------
p/k| 0 1 2 3 ...
This sequence is a bijection from the nonnegative integers to the positive integers with inverse A344537.
LINKS
FORMULA
EXAMPLE
For n = 42:
- 42 = 2^5 + 2^3 + 2^1,
- so we have the following Fermi-Dirac factors p^2^k:
5| X
3| X
2| X
---+------
p/k| 0 1 2
- a(42) = 3^2^0 * 5^2^0 * 2^2^2 = 240.
PROG
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, May 22 2021
STATUS
approved