Tree Form of Recursive Function Evaluation Steps

step

label nodes

This shows the step-by-step process of the evaluation of a recursive function as a tree. The function is defined by

f(n)=f(n+1-2f(n-1)+f(f(n-1))),f(1)=f(2)=1

. Typically the evaluation requires many steps, beginning with huge, deeply nested expressions, then changing to an overall decrease in size (with some fluctuations), until the recursive function gets its final value.