Erdős–Tenenbaum–Ford constant
The Erdős–Tenenbaum–Ford constant is a mathematical constant that appears in number theory. Named after mathematicians Paul Erdős, Gérald Tenenbaum, and Kevin Ford, it is defined as
where is the natural logarithm.For each positive integer, let be the number of distinct integers in an multiplication table. In 1960, Erdős studied the asymptotic behavior of and proved that
as.
