A hypergeometric function in which one parameter changes by 
or 
is said to be contiguous. There are 26 functions contiguous
to 
taking one pair at a time. There are 325 taking two or more pairs at a time. See
Abramowitz and Stegun (1972, pp. 557-558).
Contiguous Function
See also
Hypergeometric FunctionExplore with Wolfram|Alpha
References
Abramowitz, M. and Stegun, I. A. (Eds.). Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, 9th printing. New York: Dover, 1972.Referenced on Wolfram|Alpha
Contiguous FunctionCite this as:
Weisstein, Eric W. "Contiguous Function." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ContiguousFunction.html