In
number theory
Number theory (or arithmetic or higher arithmetic in older usage) is a branch of pure mathematics devoted primarily to the study of the integers and arithmetic function, integer-valued functions. German mathematician Carl Friedrich Gauss (1777� ...
, the Erdős–Moser equation is
:
where
and
are positive
integers. The only known solution is 1
1 + 2
1 = 3
1, and
Paul Erdős
Paul Erdős ( hu, Erdős Pál ; 26 March 1913 – 20 September 1996) was a Hungarian mathematician. He was one of the most prolific mathematicians and producers of mathematical conjectures of the 20th century. pursued and proposed problems in ...
conjectured that no further solutions exist.
Constraints on solutions
Leo Moser
Leo Moser (11 April 1921, Vienna – 9 February 1970, Edmonton) was an Austrian-Canadian mathematician, best known for his polygon notation.
A native of Vienna, Leo Moser immigrated with his parents to Canada at the age of three. He received his ...
in 1953 proved that, in any further solutions, 2 must divide ''k'' and that ''m'' ≥ 10
1,000,000.
In 1966, it was shown that 6 ≤ ''k'' + 2 < ''m'' < 2''k''.
In 1994, it was shown that
lcm(1,2,...,200) divides ''k'' and that any prime factor of ''m'' + 1 must be
irregular and > 10000.
Moser's method was extended in 1999 to show that ''m'' > 1.485 × 10
9,321,155.
In 2002, it was shown that all primes between 200 and 1000 must divide ''k''.
In 2009, it was shown that 2''k'' / (2''m'' – 3) must be a
convergent of
ln(2) The decimal value of the natural logarithm of 2
is approximately
:\ln 2 \approx 0.693\,147\,180\,559\,945\,309\,417\,232\,121\,458.
The logarithm of 2 in other bases is obtained with the formula
:\log_b 2 = \frac.
The common logarithm in particula ...
; large-scale computation of ln(2) was then used to show that ''m'' > 2.7139 × 10
1,667,658,416.
References
{{DEFAULTSORT:Erdős-Moser equation
Diophantine equations
Moser equation
Unsolved problems in number theory