Two fractions are said to be adjacent if their difference has a unit numerator. For example, 1/3 and 1/4 are
adjacent since 
,
but 
and 
are not since 
.
Adjacent fractions can be adjacent in a Farey sequence.
Adjacent Fraction
See also
Farey Sequence, Ford Circle, Fraction, NumeratorExplore with Wolfram|Alpha
References
Pickover, C. A. Keys to Infinity. New York: Wiley, p. 119, 1995.Referenced on Wolfram|Alpha
Adjacent FractionCite this as:
Weisstein, Eric W. "Adjacent Fraction." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/AdjacentFraction.html