You should see the Mathematica version: fibonacci[0] = 0; fibonacci[1] = 1; fibonacci[n_] := fibonacci[n] = fibonacci[n-1] + fibonacci[n-2] It cle

You should see the Mathematica version: fibonacci[0] = 0; fibonacci[1] = 1; fibonacci[n_] := fibonacci[n] = fibonacci[n-1] + fibonacci[n-2] It cleverly uses both = and := together. Usually people use = for immediate assignment (such as constants) and := for delayed assignment (such as functions) but this combines the two.