Amenable Number
A number
is called amenable if it can be built up from integers
,
, ...,
by either addition or multiplication such that
 |
(1)
|
(Tamvakis 1995).
The solutions are the numbers
such that
or 1 (mod 4), excluding
(Lossers 1998), giving 1, 5, 8, 9, 12, 13, 16, 17, ... (OEIS A100832). For example, 5 and 8 are amenable since
REFERENCES:
Lossers, O. P. "Solution to Problem 10454. Amenable Numbers." Amer. Math. Monthly 105, 1998.
Sloane, N. J. A. Sequence A100832 in "The On-Line Encyclopedia of Integer Sequences."
Tamvakis, H. "Problem 10454." Amer. Math. Monthly 102, 463, 1995.