such as x_n, what it in fact denotes is a Function Application x(n).
I (Iago Leal de Freitas) must comment, perhaps to the abhorrence of my Haskell readers, that Iām rather fond Fortran. One thing I like about it is how the language uses the same syntax to denote Vector Indexing and Function Application: x(n).
šŗ
Sequences are Functions That Do Not Forget ā Memoization: The basic idea is just to keep a table of previously computed input/result pairs. [ā Table Lookup ā Table Lookup and Dispatch]