I am interested in some general ways of defining sequences s[i]. 1. s[n+1] = f(s[n])*s[n-1] + f(s[n-1])*s[n] If f is the constant function "1", then this is the Fibonacci sequence. 2. s[n+1] = g(s[n]){s[n], s[n-1], ..., s[0]} Here, g is a function that has a number as an input and produces a multivariate function that is applied to previous sequence values. g could be, for example, a linear function with k terms using coefficients derived from s[n]. 3. s[n+1] = g(s[n]){t[n], t[n-1], ... t[0]} where t is a sequence defined on i=0...inf. As before, g is a multivariate function derived from the number s[n]. Is there some standard terminology for these methods that I could use to find prior work? The keywords just cause Google to latch onto well-known recursive sequences. Thanks, Hilarie